FNB - Bad debt hand over, but I've never used the account

I opened a business account a few months ago, which I have unfortunately not been able to use. Today I received a call from debt collectors saying I owe FNB money and I've been handed over. I have been handed over to SDK attorneys for debt collection. More so, FNB has not given me any notice that I owe any money. What makes it worse, is I phoned FNB business customer service and have been on hold for 35 min, and counting. This is by far the single worst customer experience I have ever had.