Transaction disappeared and balance doesn’t show like it should.

https://live.blockcypher.com/btc/address/3FGpQq5nA6SFRMDFGszx67vTDwpDGqdCG4/

Balance is 0.02743974.

In the wallet is says that balance is 0.004399.

It gave me transaction hash ab8d17e9f8243b0d328d61c481b2b33439719a6079599b26b732e185298db8a6.

And now it has disappeared and says there is no such transaction.

What should I do? I sent message to coinb.in but they have not answered yet.

I'm using P2SH address.. I will try your suggestion..

Can I import this whole address to Electrum??

I need to do the following. I'm true noob at this. The instructions were ''sign btc address'' so that I can prove I'm the owner of the wallet.
I also need to include a message with the signing.

How can I do this? I found other tutorials but not one using the coinb.in..  

I also know how to do this with Electrum but don't know how to import my Coinb.in wallet address, so I cant do this in Electrum.

I have tried to learn this but since English is my 3rd language it's very hard to find and follow a tutorial how to do this.

I will give small amount of BTC to someone who can solve my problem, leave your wallet address with your advice