BrentMarkets demanded a 13% fee before releasing my ETH

I traded BTC and ETH through BrentMarkets for more than a year and was initially able to make one or two withdrawals. When I tried to close my account and withdraw the remaining ETH, the platform blocked the request.

BrentMarkets demanded a 13% blockchain gas fee and gave changing explanations involving congestion, account closure, and administrative fees. I am posting this because I do not believe an invented fee should be required to release my own balance.