https://crypto.com/exchange/document/fees-limits
That wouldn't be an excuse either, even if they don't batch payments and they would a 1 input two outputs transaction it would still be enough to pay close to 200sat/b even more f they are batching them with 50-100 outputs as most exchanges do.
But even if they would need to pay that sum they could simply state that in their ToS, they charge 0.0004 plus additional fees if x,y,z happens.
Too bad OP has chosen to open a topic, complain, and then never come back again providing a minimum of additional info, till something like that happened I tend to believe SFR10's scenario, the user looked at the tx fee and thought he was changed that, probably he realized this later, thus the silence afterwards.