Hello , Denis.
Unfortunately, we are forced to require you to pass KYC, these are not our requirements, but the requirements of the regulator. This is a standard situation when you need to pass verification, especially since before the transaction you agreed to the terms of exchange and verification. The same conditions apply to all exchangers that care about the safety of their own and their clients, in other cases these exchangers send non-clean cryptocurrency to their other clients. Please pass KYC verification.
Why do you allow users to proceed with the exchange without verification? If you force KYC verification, then don't allow users to make any exchange with KYC verification. So that you don't need to make drama later. You can't raise a flag against a transaction if it's fresh and has been claimed by the OP. I admit OP marked onagree about your terms, which included KYC verification. But since OP isn't agreeing to verify KYC, and he forwarded from Best_Change, where you are not tagged as a KYC exchange. A mistake happened by the OP, but there should be a solution. Either complete the exchange or refund his funds. Because the funds aren't yours. You don't have the right to hold it. Return to the same address as said by the victim as well.
I will ask OP to please create a flag; from my end, I will also create a flag as well. For now I leave a negative red tag for the exchange. I will remove it when OP gets a full refund or exchange.
Here is the flag link: