@OP, you should give some updates if this issue had been resolve or still pending as of this moment.
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?