Unfortunately Bitcoin is not fungible. Unfortunately, since the history of each and every input is viewable by anybody, various businesses can easily become picky in where your coins are coming from or what you are doing with them.

BestChange's case is not unique. Afaik some bigger exchanges may be doing the same. BestChange could mark these exchanges they redirect to, in a way or another, but... there will still be some who cannot read the signs and such classification may also not be great for the business.

What has happened to OP is pretty much not unique also.

I don't understand why people don't read everything thoroughly before sending their money here and there.
I don't understand why people don't test new services with smaller amounts of money, which don't have the potential to "hurt the budget" much in case things go wrong.


Since the service OP was using has stated that it uses KYC/AML, it's somewhat at the limit between scam/stealing and not (although I guess that there's a bigger chance they keep those funds instead of sending them to the authorities). I would certainly avoid them, but I'm hesitant in calling them scammers.
OP should have been taking more precautions and avoid them earlier.