Consolidate FBM Accounts

I have two seller accounts. I don’t know how this happened, but when an order comes in, I sometimes can’t find the customer name and address to print the label and packing slip. Then I realize it must be in the “other” Seller Central dashboard. I’ve opened several cases, but no one there (wherever that is) seems to understand the question or problem. I hope that someone here can provide an email address or phone number that will get me to an Amazon associate who can truly help consolidate the accounts under one business name and password.