He's not online since April 4, and I'm pretty sure he will post here again if the issue is not yet resolved. But I'm not surprised if he just gives up and then decides to no longer continue his complain here because that doesn't really helped his case.
Maybe contacting or posting on Changelly thread is better to get the attention he needs.
However, looking at his transaction ID, it seems that the TX itself is not valid due to insufficient funds. So maybe, Changelly doesn't hold enough funds in their hot wallet to send the USDT to OP after he exchanged it?
I got my Tether after the 2nd time contacting support. So a bit over 48 hours after reporting problem.
Yes, it seems the error was originally caused due to insufficient funds on USDT from their end.
Just wanted a quick exchange, would probably not use changelly for bigger exchanges in future.