About a week ago, I have been "banned by Pretendeer [MCT] for permanently with the following reason: Alt."

First of all, I have never had or used an alt account. If you look into my TF2OP-Profile, you will see that my trades did not exceed the trade limit, thus making an alt account for me completely useless.
Second of all, I live in germany. IP addresses in germany are constantly rotating, which may have caused another TF2OP-User from germany to receive my address.

I tried to add Mr.Rager on Steam (as hinted in the ban page), only to find my request denied two days after. About five minutes ago, I found out that my appeal on the ban page has been rejected as well.

I would like a full explanation of why I have been banned (including technical information)