If you sent as F&F payment there is still some chance that you are able to chargeback, but you'd have to claim that your account was hacked at the time of the transaction IIRC, which I don't recommend doing since it probably breaches some form of ToS.
There were plenty of warning signs available that you should have recognized to deter you from trusting this guy and going first, imo. Why would you deal with someone with no reputation, sending with F&F? Use escrow, or send as G&S instead. Also, the fact that he's selling at such steep discounts suggests that he probably did not obtain these credits completely legitimately in the first place, which even escrow won't mitigate the risk of, and can land you in some trouble in certain circumstances.
It seems like that the user
Jean_J is highly likely to be an alt of the same accounts. He's the only one that is vouching for the seller (moonu296) on the thread.
