Any advice or contacts that could help would mean a lot.
Sorry about that OP, but I heard man similar cases related with Changelly .
You should really stop using Changelly, especially for large amount of coins like in your case.
I would suggest using alternatives that are decentralized and can't seize your coins, or you can use services
that provide some kind of guarantee for swapping coins on exchanges, for example OrangeFren is one good example.
For these services like Changelly, the best thing is to one avoid them in the first place and if they want to use any legit one, still then only swap small amount of funds at one time. However, this may lead to an increase in the fee if they do many small transactions.
By the way, is there any service that is the best one and has not been reported to have any scam accusations?