Always delayed when you want to close accounts

I received a letter of demand from FNB business. I paid the full outstanding balance. Which was R1750 of bank charges. No overdrafts no plans. Trying to close the accounts is a nightmare. Now the first want Fica documents but I'm blocked on online banking. Please close all my accounts. I can't be calling time and time again to close accounts.stop the games it's really annoying. Stop the letter of demand. I owe you nothing.