A.P.O account not set up

Wow I have no idea where to begin. I'm fed up with Nedbank is all I have to say, I have opened up an account with fnb which I'm very happy with and will be shutting down my nedbank savvy. About 2 years ago I app**** for a credit card and had an A.P.O set up on my account, about a year after I had been debited for this card I started being debited enormous amounts and charges and receiving calls from the call centre telling me \I'm in arrears". I had spoken to numerous call centre agents and many have told me my account has NOT been set up as a debit order. I'm fuming from this as nedbank has gone against my will and nothing was done about this and I'm still being debited large amounts and being told I have not been paying. """