The seller try to scam me

Hello guys,
I bought black dieci there is 6 days now, but i bought it on steam and i wanted to buy it on PS4 (it’s a big fail …) so i telled the seller to cancel the order 10 minutes After i bought it if it’s possible but he marked that he delivered the item one day after. So I made the transaction on hold to cancel the order.
But one of these friends it is renamed as me on steam by taking the same photo of profile and he gave him the object by taking screenshots. So To prove that it was not me, I added it to take a screenshot of the steam chat but he refused the friend request. The post is on hold since 3 days.
What can i do ? I payed this dieci 80$ and I want to get my money back.

80$ for black dieci? are you crazy?

I really needed it …