Amazon Advertising Portal Support – Employee Gone

We had an employee leave our company who was the primary admin for Amazon Seller and Amazon Ads. Because she set up multi-factor authentication with a number that no longer exists, we can’t log in to the account.

I have been trying to get Amazon support to give me full admin access for months. We just keep going in circles. Now our company is changing credit card providers and I desperately need to get admin access so I can change the billing.

Anyone out there have this problem? Anyone have any ideas?