So what should I do if I think a scammer is using the Vote on Reviews with multiple accounts to scam

SteramTrades has no moderators or support. All negative comments are removed by the community through voting.
Also, the case you described usually indicates that you were talking with an impersonator and did not check them through Augmented Steam first. Someone with 1000+ rep won't scam people for a cheap 3-dollar key. (By the way, nor would have it been realistic to send an 8-dollar Slay the Spire key for a 3-dollar PoE1 key.)

first is against the rules to post his name here, second i have made 2 trades with him all successful he/she seemed like a professional seller to me, so are you sure with your claims?

EDIT you were trading with Neintanke on steam but you are reporting PalkoVvodets i am confused, am i missing something?

it appears that someone else have scammed you

They aren't even the same person... I mean if you're gonna link people profiles with accusations of scamming at least make sure they're the same person.

Looks like you gave your key to Neintanke , but for some reason PalkoVvodets is at fault? What?

Who did you speak to on steam? (their profile link is the same as who you post?)

you are right I got the wrong account on steam trades thanks for pointing that out. You are right I am a freaking moron. Sorry about all this.
I must have accidentally clicked on one of the people who gave him a positive review and got confused. I am just a little stressed about getting scammed, but that is no excuse for claiming I was scammed by the wrong person.

I am really sorry.