I knows a user on IGN who got banned many times. He then got a permaban, but then he was unbanned. He then got another permaban, and then after talking to the mods, he was unbanned. I don't know if he is banned right now, but he was active a while ago. I also know another guy who was banned multiple times, but I don't think he was ever permabanned.

I dunno about your case though. The user I was talking about was banned for spamming mostly, so it may be totally different in your case. I'm not a mod, so I really can't check, but good luck anyways.