FNB *****ing Money from my account.

With Credit card upgrade FNB deducted money from my Private and Wealth credit card, already *****ing R4000. After the Private Credit card was closed the remaining R16000 was not transferred to my Wealth card therefore *****ing another R16000. Then asking me interest on the ****** R20 000. I’ve phoned FNB only to speak to *********** staff that do not listen. Who do I contact to escalate this?