NAME CHANGE OF ACCOUNT HOLDER

I HAVE BEEN REQUESTING VODACOM SINCE AUGUST 2014, TO CHANGE MY ****EN NAME TO MY MARRIED NAME TO NO AVAIL THIS DESPITE SENDING EVERY MONTH THE MARRIAGE CERTIFICATE AND ID. 2 ACCOUNT INVOICES THAT ARE SENT MONTHLY, ONE HAS NO SURNAME AND THE OTHER STILL HAS THE ****EN NAME. EACH MONTHLY TELEPHONIC CALL A NEW SERVICE REQUEST NUMBER IS GIVEN AND A PROMISE TO CONTACT YOU IN 2 DAYS TIME WHICH NEVER HAPPENS. WHAT ELSE DO YOU NEED TO HAVE JUST TO CHANGE A NAME???