Formal complain regarding Nedbank credit card payment service

Please avoid taking credit card with Nedbank. They put you on arrears even when you are paying every month. Once you are done paying they will never coear you and give you clearance letter. Instead they will keep on debit and when you call they will say we will refund and give you clearance letter but you won’t see that happening. I have been waiting for coearance letter and my regund since september