I had this exact same thing happen. I wanted to try out some advertising so I put up in $20 and an ad for some shitty clickbank book. Of course it went nowhere so I deleted the whole campaign and left it at that. I went back to check out adwords a year later and my account was banned. I tried to appeal but they just told me that the anyone who ever had those urls as ads were banned and there was nothing they were going to do about it. Now that I'm going to get into Android development I'm think I'm going to try what you did, different address, VPN, etc. I'm moving in the summer so it won't be so hard.