Oh man. What game are you having trouble with now? Maybe it's best to contact them even though I don't think they can change the system much.
As far as I can tell, the only way to up your rep again is by playing online multiplayers and then not getting reported. Do you have any other online multiplayers in the meantime?
--> This guy had the same issue and he found a way to improve his rep again but it's basically the worst solutiuon ever. Still, as a last resort maybe?