This is the only scam report I could find against you https://www.mpgh.net/forum/showthread.php?t=1146948
If you want your ban to be lifted, you'll have to create a giveaway equivalent to the amount you scammed, or the item(s) you scammed. A winner will be picked by a middleman in 3 days. You have to create a giveaway because the user you scammed seems to be inactive.
https://www.mpgh.net/forum/756-giveaways/
Once completed, your ban can be lifted.