MTN IS DIGUSTING. NO ANSWER FROM CALL CENTRE!!!

LATELY MTN HAS A HABIT OF ROBBING ME FROM MY AIRTIME. YESTERDAY I HAD A BALANCE OF ONLY R6 WHEN I CHECKED AGAIN I HAD NO AIRTIME, WHEN I CALLED THE CALL CENTRE THE LADY GOT RUDE AND INSIST I MADE A CALL, I TOLD HER I DID NOT MAKE ANY CALLS AND NOTHING IS SHOWING IN MY CALL RECORDS. THIS MORNING I LOADED A R30 AIRTIME AND NORMALLY I WOULD BUY DATA AS WELL, BUT IT DID NOT ALLOW ME AS IT KEPT GIVING ME SOME ERROR MESSAGE, WHEN I CHECKED MY BALANCE AGAIN IT SAID I HAD R3 LEFT???? AGAIN NO CALLS WERE MADE. I TRIED CALLING THE PATHETIC CALL CENTRE AGAIN AND NO ANSWER FROM THEM FOR THE PAST HOUR NOW. i HAVE BEEN WITH MTN FOR THE PAST 10 YEARS AND NEVER HAD ANY PROBLEMS UNTIL NOW. MY CONTRACT ENDS IN 3 MONTHS TIME AND I AM SERIOUSLY ACTUALLY CONSIDERING CANCELLING IT AND CHANGING TO ANOTHER NETWORK. i DON'T MIND PATHETIC OR RUDE CALL CENTRE AGENTS BUT I HATE THE FACT THAT I CANNOT GET HOLD OF THEM FOR SUCH A SERIOUS MATTER AND THE FACT THAT MY AIRTIME IS DISAPPEARING FOR NO APPARENT REASON IS DISTURBING TO ME.