***** calls for kyc details

Today ive been phoned from durban im in pretoria .this person is phoning me from MFC NEDBANK .telling me that i need to do my kyc or my account will be closed .i contacted Mfc headoffice,i Jhb apparently it was not from them but maybe from Nedbank them selves which i dont have an account with ! Seriously , why is staff taking chances on ***** from this bank!