Tell me friend, why should moderators help you out in doing something that isn't endorsed by the forum (and is discouraged)?
If you can't provide a signed message from an address staked by that account, no amount of easily faked screenshots will help you.
But they can just contact the seller and verify the deal - he is member status, I dont think that member will risk of his account to cheat on Jr.member acc for 30$
Seller contacted them already - i can shoot video from telegram of deal also