FNB Personal Loans/ Covid 19 relief plan

I'm sick and tired of calling and sending emails to FNB. I have been begging them to change my banking details from their side to be able to debit my new account. I have called 4 times and sent numerous emails to do this but its still not done. And now they have the nerve to put the arrears of that account on me. I cannot wait to pay up this loan and be done with them. I cannot believe how difficult it is just to do a simple change.