Mummy's Gold Casino - Deprived me the winnings $261 and blocked my account

I registered, made a deposit of $36 and received a 100% Welcome Bonus.
I played several days in different games.

I carefully read their terms. I did not violate any of them.

As per T&C the max allowed bet with an active bonus is $8. My max bet was $8.

I fulfilled the wagering requirements of the bonus and finished with $261. I requested a withdrawal.After six days they blocked my account.
I asked Adam in live chat to explain the reason, he said my account was locked as per management decision.He refused to explain on what grounds they confiscated the winnings, saying only that is internal decision and I will be not able to reopen account again with them.
I do not agree with them. I used my personal data. I used my personal ewallet for deposit. I did not violate the terms.
I demand that they must provide evidence on the basis of which they confiscated the winnings.