I hopped in a Search and Destroy server, and I got a bar saying such and such percent done. I get out of it and I have all this stuff unlocked I didnt earn. I dont want this shit. I didnt earn it, and the guy who did it is denying everything. Is there someway to reverse this?

Edit: If it isnt obvious, he used a stat editor. I have his Steam tag, if that's any help.