I had a *****ulent transaction that went through my credit card on the 19th Feb this year for R21,000

I had a *****ulent transaction that went through my credit card on the 19th Feb this year for R21,000. I did not authorize it and immediately reported it to the ***** division. It is now 3 and a half months and I have phoned many times, often holding on for 40 mins or more and not getting an answer, I have emailed several times...also no reply. I am so frustrated as I have not had a single word of communication from the bank re this matter. It is now impacting my credit card with interest piling up per month. I don't know where to turn next and I am extremely frustrated with Nedbanks lack of service.