I have already kept sending message to them, this was my last resort.
Be patient. Being an admin of a forum of such size is hard.
Besides, are you sure that the signature checks out? I tried verifying it online and on electrum, but both methods didn't work.
Also, did you read the hacked account recovery thread thoroughly?
I'm fairly certain that based on your statements in the OP, you've sent multiple PMs instead of just the one that is supposed to be sent. That could well be the reason why you're getting ignored. Also, did you follow the exact template as posted on the thread? You did not include a link to an unedited post which you posted that address in the signed message you have here. As a general rule of thumb, if you're getting ignored, it usually means that you've done something wrong.