Here are some very important concepts to learn if you are going to continue to use Bitcoin. Please take a moment to read through this post:

The reason that "blockchain" couldn't help

The company called blockchain that runs a website called blockchain is not THE blockchain.  Imagine if I were to create a company called "Internet Services", and that my company has a website that lists the names of all the internet email providers that I know of.  That doesn't mean that I am in control of THE internet or of any of those company's email services.  If you were to send an email from Google's gmail service over THE internet to someone else's AOL email address, and that email were to fail to arrive...  Calling my company that publishes the list of email service providers isn't going to accomplish much.  I'm not Google (the provider that you sent from). I'm not AOL (the provider that you sent to). I'm not THE internet (the technology that you used to send the email).

That's what happened when you tried to contact "blockchain".  There is a company called "blockchain". They provide a website that lists all the blocks that they know about in THE public blockchain. That does not mean that they are in control of the blockchain, or any of the services that make use of that public blockchain.  When you sent bitcoins from Coinbase through THE blockchain to someone else's service and those bitcoins failed to arrive... Calling the company that publishes the list of known blocks isn't going to accomplish much. They are not Coinbase (the service provider you sent from). They are not the service provider that you sent to. They are not THE blockchain (the technology that you used to send the bitcoins.

It can be confusing that there is both a technology called blockchain and a company called blockchain.  The company did not create the blockchain (they came along later and just named themselves after the existing technology).


The reason Coinbase couldn't help

Coinbase provides you a place to acquire bitcoins, and sends them elsewhere on your behalf.  Bitcoins are not an electronic "account" like you are used to with a bank.  It works more like an electronic representation of a CASH (paper and coins) transaction.  If you pay someone $100 with an electronic account (like a credit card) you can contact the company that provides that account and they can cancel the transaction.  If you hand someone a $100 bill, and they walk away...  The money is gone.  There is nobody to call.  The only person that can give you that $100 back is the person that you gave it to.  When you "sent a transaction from coinbase" what actually happened was that you asked coinbase to give some of the bitcoins that they were holding on your behalf to someone else (more specifically, to a bitcoin address that was not under their control).  Once they turned over those bitcoins, there isn't anything coinbase can do to get them back.  The only person that can give you the money back (or access the money at all) is the person (or company) that controls the address that you sent to.


The reason the receiver is having difficulty getting their service to fix this

Managing control over crypto-currency requires the use of digital keys.  Each address has a key that will allow controlling of any funds at that address. The ONLY way to control those funds is with that key... AND... ANYONE with control of that key (or a copy of that key) can control those funds.  Now imagine you run a service (similar to Coinbase) where you are managing the funds of thousands (or millions) of people on their behalf.  That means your service has thousands (or millions) of keys to keep secure. If a disgruntled employee can get their hands on any of those keys, then they can steal funds from your customers.  Therefore, you need to have extremely strict control over who can access the keys and how they are accessed.  Also, if you were to lose any of those keys, the funds would become permanently inaccessible.  It is possible to copy keys, but it is not possible to re-create a key without a copy of the original. Scammers, thieves, and other criminals will contact the service regularly, pretending to be a customer with an unusual situation and ask them to do something out of the ordinary with the keys in hopes of gaining control of the funds or tricking the service into sending funds.  It is this high level of security and caution with their customer's funds that makes it time consuming and difficult to subvert their normal security processes to acquire a BTC key for a BCH address.  Because of the time, difficulty, and risk... many services will either refuse to help or will require a significant fee to help in a situation like this.

However, the receiver's service is the ONLY entity that CAN fix this

Since the receiver's service is the entity that controls the digital keys of the address that you sent to, and since it is impossible to control funds without that digital key... You are at the mercy of the receiver's service.  If they are unwilling to help you, then you either need to find a way to force them to help, or you need to consider this an expensive lesson in being careful about where you send your crypto-currency.

Crosschain Deposit Recovery

Crosschain - A deposit of one coin to a different coins address is considered a crosschain deposit

Bittrex will only attempt to recover crosschain deposits that exceed $5000 at the time of deposit, within 7 days of the deposit and will charge a 0.1 BTC for this recovery. Recovering coins crosschain is an inherently dangerous and time consuming process.

Due to our new Crosschain Recovery System, the minimum requirement for crosschain recoveries is $3000 at the time of deposit for the following crosschain pairs:

    BTC to BCH
    BCH to BTC
    BTC to USDT
    USDT to BTC

Just because a site has HTTPS, doesn’t mean you can automatically trust it.