if you are legit getting scammed, email onlyfans with the proof. You will get your money back if you can prove you were lied to. Its the only way the agencys/girls will learn.
If they are offering to sell you something, do no beat around the bush. Straight up ask "does this show naked tits? no covering?" or whatever else they are offering. If they say yes, and you buy it and its not what it was. Screenshot the chat window, and provide the proof to OF. Now on the other hand, if they aren't willing to verify thats whats in the set, then you know straight up its a scam and can avoid purchasing all together.