Amazon Marketplace My trial version seller account mysteriously turned into a chargeable seller account without my knowledge Internet

Some time ago I tried amazon's seller account trial version. Then I forgot about it. I continued to buy things as everyone else from amazon.com. But then I decided to sell a book. When the book was sold, there was no payment dispersed. When I looked into it, I noticed a charge, negative amount of $-173.93. The wouldn't pay because my credit card No. was not valid anymore. Not knowing what was going on, I updated my account with the new credit card info. Not only they did not pay me for the book they sold, they charged my credit card $173.93. After back and forth dispute, they agreed to credit that amount, that was two months ago. After asking them again, I find out that they have blocked my account, according to them, they will not pay up on account which are blocked. So now I have to keep on fighting for this. And of course you can't talk to them on the phone, only email. Watch-out, when opening accounts.