Rejection of Amazon Business Account

Hi there,
I am in desperate struggle here, any help is much appreciated.

I am the manager of an LLC company selling on Amazon.
I created a buyer account and wanted to convert it to a business account (to reduce taxes for high volume of purchases etc.)

I got a rejection mail saying that: my request has been rejected because my account is related to an another buyer account that was closed by Amazon.

The thing is, I did not have any other business account and I just opened this one.

What can I do in that case?
Should I create a new buyer account using a new computer and a different internet connection?

What actions should I take to prove myself right?

Do you think the problem is related to my LLC company, Should I start a totally new company?

General customer representatives are not able to help? I talked with an account specialist but he only repeated that the decision is final and there is nothing to be done. How can I contact an account specialist? Do you know their e-mail addresses?

Thanks a lot.