FNB Debt Review Department not getting back to me, after I left two messages

Hello Peter Me again with the same company.My struggle with FNB is real .I receive bad service on every encounter I have with this bank. Since Wednesday I have been calling the FNB Debt Review depart, however their lines are always busy, I never get through a service agent. I have left two messages already to be called back, no one bothered to call me. Today I decided to go to the bank to request a closure letter for a loan I have just finished paying. The guy at the door at bank City in Johannesburg told me I should be assisted by the loan department over the phone. I explained to him , I have already tried that, he also gave me an attitude saying they don't do that, basically that's not his problem. I am out of options , My airtime is finished from calling this bank. Not to mention I need this letter urgently for my Debt reviewer to adjust my payment plans accordingly. please help .