Livid.. poor service

Nedbank.. has done me wrong and their consultants with their non-challant service is giving me a headache.. My cc with Nedbank normally deducts every end of of each month.. End of August and few days Nedbank cc does not deduct i call Nedbank to remind them, the consultant tells me all is update no need for deduction even though it shows minimum due.. because I made 2 payments middle of the month it has acknowledged those payments.. ok I continue with my life. Mid September I receive 4x sms immediate payment is needed for my cc I’m shook..double of the minimum I was told to pay of which I was advised all is well and up to date I call, the consultant says to all is well i see the 2 payments that were made I give the lady dates of the sms.. of the immediate payment , consultant responds I don’t know why .. I apologise. End of September I make payment to my credit card.. of the minimum payment due cause I’m avoiding the confusion they made between August and September. I wake up this morning my current account is on - negative because of Nedbank..cause today they decided to deduct the same amount that has been paid already.. I call the consultant she seems lost and says I should transfer back?? Transfer what back I’ve made payment and Nedbank has acknowledged my payment if I make another payment of that amount it will taken by my current account were as Nedbank is the one to fix the confusion they keep on making my account is sitting on negative due to Negative and the consultant does not seem to care cause Nedbank did not do her dirty and same Nedbank has the audicity to tell me update my account it’s them who should update my account.. this consultant keeps on saying my Credit card is updated I know it is my cheque account is not updated due to a payment that went through which is a double payment Nedbank fix this.. immediately