As long as BadBear trusts him nothing can be done.
Not true. If 2 other people on the default trust list exclude him, then he will no longer be in the default trust network.
Now that you have seen this thread, can't you just look at the IP's used and everything to verify I am not the alt that he claims I am ? Kind of feeling ridiculous that even the forum doesn't do anything for such trust abuse that Quickseller is implementing.
You can easily use a Tor or VPN. Also even if a scammer account was sold, negative feedback should not be removed. Proof for this are plausibly manipulated. Many threads will popup if negative feedback are removed for these kind of things. I feel sorry for your loose but you will have to live with it. I suggest you to join a campaign which accepts users with red rating.