How Can We Close Our Account If We Are Unable to Log Into Our Account?

Each member of our company has had his/her permissions removed by Seller Central due to an error made by Seller Central - not due to anything we did wrong while selling to our customers. I have tried for over 6-months to correct this issue with no results. We still cannot log into our account to update information, fulfill orders, offer support or update our products. Even the CEO of our company has had his permissions removed making it impossible for us to sell on Amazon. Therefore, we wish to close our account immediately so we can stop losing money. Each month our credit card is charged for the privilege of using Seller Central, but we CANNOT log into Seller Central. This needs to stop! We wish to close the account that we have had since 2011. How can we do this if we do not have the permissions to log into the account?