Unauthorised changes to my banking

I went into a store to do some grocery purchases, only to be told in front of a crowd of people that my card was cancelled and I was liable for arrest. I called Nedbank to find out that the credit card department has taken it upon themselves to cancel my current credit card and replace it with an AMEX card without even bothering to inform me. <br> <br> I have spent 2 days in the bank and several hours on the phone and nobody has been able to explain who made the changes without my authorization.<br> <br> To add to this my account statement is being sent to my nephew's email address after numerous requests for my statement to be posted to me<br> <br>