Sorry about your loss.
At least they responded and make you to understand that your funds can not be recovered and that will bring peace of mind, the only thing i do not like about the whole process is that it took more than one year to inform you about it.
That was a real problem using 3rdparty wallet aside that you dont own the private key. You will not getting back the coin that you accidentally send it wrong.
But i know they are able to retrive thay bch since they have a control to the wallet.