if it's about being hacked then support and security team should have explained it, Also OP account seems to have the same balance -well, until the account was closed-
it's up to 1xbit.com team to explain, regardless of the reason, I think they should've already presented their case - regardless of it being bonus abuse, abnormal ip activity, abuse of games vulnerability etc etc... -- Not making any argument is very bad for the public image IMO.