Cannot Close Paid Account

I had a revolving loan with FNB.

Called their collections team to confirm amount to close account and to date the account has not been closed, even though I paid it off.

How do you hand someone over when they have been 1. consistent in paying and 2. asked for the account to be closed?

I am so disappointed and distraught because they seem to think that handing me over and then having their managers not respond to mails is acceptable.

I am going to complain everyday - on every single social media platform - until I resolve this matter.