Missing payment still no assistance after 36 days!!!

I have made a payment on my Amex credit card on 31/10/2019. Nedbank made promises to contact me, made me send a single proof of payment to several email addresses, just to tell me the funds have been returned, whereby I contacted my bank, and they investigated and sent me proof that the payment went through successfully. This then only means that my money was taken by Nedbank and not refunded back. Everyone I contacted has been of no help to me whatsoever.