They banned you from Telegram because they already know about the bug from your email so they don't think it's important to keep you in their group. If a casino ignores their customers' complaints like this, it's really unacceptable that they're ignoring such a serious issue. Since they are ignoring your complaint, there is nothing you can do if they face financial damage. It's good that your problem is solved, so you don't have to worry about other things anymore, they will take care of themselves.