My Mturk account was banned but I never had one.

So, I wanted to sign up for a Mturk account. Logged in with my (German) Amazon account and got the message that it was not possible to create an account, because my account was banned. Which is paradox, because I never had a Mturk account.

Can anybody tell me what is going on there? I tried contacting support per mail, but never got an answer.