You were banned by @Flengo for the reason you've already pointed out. Here's the link to the scam report which was made against you and got you banned for scamming in the first place: http://www.mpgh.net/forum/showthread.php?t=1116911.
Quoting Flengo's post:
Given his statement, yeah, I believe you're going to have to refund the user who got scammed by whoever hacked your MPGH account, who was @gachiGASM.Hacked or not, he is responsible for what happens through his MPGH account. If issues like this are reported in advanced, precautions can be taken to prevent scams from happening from hacked account.
He has been permanently banned.