We do not have any information regarding their liquidity structure. Only because they are around for some time now does not mean that 7,7k USD is not major money to them. How do we know that they have not have been running break even after all their costs over the past years?
Whether the amount is 7k$ or less does not matter because it is unacceptable to freeze any player's money without clear violation and providing evidence.
Also I find it suspicious to ask for KYC after you won the bet, why didn't they ask for it when they first registered?
Also, if they say that you used a scanning program, they should provide proof that you are actually using a scanning program. It is better to put it in this thread for everyone to see.