one of the other reasons ,why you should shift bank

I have an account with cepitec ,under loans I have Access Facility and credit card ,so now I mistakely made payment in to my credit card now I can't reverse it this is through the app ,I decided to call the call center ,the consultant told me I can't reverse it if I have outstanding errors outside capitec bank ,so here is the part I don't understand ,my account with capitec is update .where does my outstanding errors outside the bank affect my account , where they get there installment every month without fail . I feel it's unfair ,I have been hearing stories about this I chose to stay now I want to go to other bank