It all depends on the situation and how dirty the money is, if the exchange agrees to return the money without documents we will do it, if not, then no, everything is written in our policy AML
We do not have a limit on the amount if the money is clean you can exchange even 100,000 and we will not ask anything, if our system has considered your money dirty we will ask you to pass the cousin using the service
https://sumsub.com/, if to solve your case we need something else we will communicate with you by mail or via telegram.
Is a refund possible in this situation, in the case the user refuse to send docs ?
I think this information should be included in the terms. Included your partner sumsub, so the customer may know everything prior to the exchange.