1. They were probably only just submitting your transaction to the free antpool transaction accelerator anyways, so they are basically charging a fee for a service that was actually completely free to access for anyone.

2. They did not refund customers that did not get their transactions confirmed within the timeframe they promised.

So even though they couldn't do anything to your actual transaction, they were scamming probably hundreds of people from their money.

And now, he's not responding to anyone anymore, which is disgraceful.