Unfair treatment

Had a cheque account with Fnb which I stopped using in 2017 if I’m not mistaken, used to get my statements by email which Fnb stopped sending, was shocked when I got a call in November that my account was handed over apparently I’m owing over 5k, I sent an email to Fnb enquiring and got a call from a premier and banking consult with ref number ***, I raised my concern that it was not a matter of money but of principle cos should I have continued to receive my monthly statements would have been aware that the account was accumulating interest and would have addressed it, instead Fnb let the account to accumulate and failed to notify me instead they handed me to lawyers, the consult promised to investigate and get back to me which didn’t happen it has been more two months without any feedback from Fnb instead I get harassed by lawyers every day, to an extent of calling my husband. Will never go back to Fnb again and will continue to tell anyone who cares to listen what a f**** Fnb is by the way my husband is and Fnb black card holder and is in the process of moving to another bank.