Disappointed Client

I am disappointed with this bank, I have been banking with FNB for almost 26 years and I called them on the 17 Dec 24 and requested to reverse and stop a debit order that I have cancelled with the service provider (Isabella Garcia) this service provider is really ****ming people, yes I have signed a mandate but I cancelled with the service provider and they stopped for three month but they started again after that three months and when I called FNB I was told that someone will call me and today its the 27 Dec 24 and no one ever called me, the ones I talk to when I call its nice consultants who are willing to help but they cant because of the bank mandate. I am disappointed with this bank and if they are not going to assit me as their client and choose the service provider then I am going to take my business somewhere else because I have always known that FNB does not assist their clients, I know that personally but because I am a very loyal client I stayed and also because their app is friendly BUT this is making me ANGRY for them not willing to assist.