MISSING 1GB

ON SATURDAY THE 1ST OF AUGUST MY TOP UP FROM MY CONTRACT CAME IN AND I PROCEEDED TO CHECK MY BALANCE.. I GET 100MB DATA AS WELL AS R200 AIRTIME... I BOUGHT 1GB FROM THAT AIRTIME AND I WAS LEFT WITH R51.00 WORTH OF AIRTIME.. I MADE 5 CALLS AFTER THAT.. AND ONLY WENT ON TO FACEBOOK A 7:20AM THAT MORNING.. I WENT OUT TOO RUN A FEW ERRANDS. I AM NOT SURE OF THE EXACT TIME, BUT SMS'S STARTED COMING IN TELLING ME THAT I HAVE ONLY 4.36 MB LEFT OF DATA AND IMMEDIATELY AFTER THAT MORE SMS'S CAME IN TELLING ME THAT MY DATA HAS BEEN DEPLETED.. PLEASE EXPLAIN TO ME HOW IS THAT POSSIBLE WHEN I DID NOT EVEN USE MY PHONE ON ANY SOCIAL MEDIA SIGHTS AS I WAS DRIVING MOST OF THE DAY.. ON SUNDAY MY 100MB HAD BEEN RETURNED AS WELL AS MY AIRTIME, BUT MY 1GB OF DATA IS STILL NOT ACCOUNTED FOR AND I CALLED CUSTOMER SERVICE AND THEY THEMSELVES COULD NOT EXPLAIN TO ME WHERE MY 1GB OF DATA HAD GONE... I WANT MY DATA BACK.. THIS IS THE FIRST TIME I HAVE HAD A PROBLEM WITH VODACOM AND I WOULD HATE TO HAVE TO MOVE TO ANOTHER SERVICE PROVIDER... I HAVE WAITED FOR THEM TO GET BACK TO ME AND NOTHING HAS HAPPEND... I AM REALLY NOT IMPRESSED WITH THE MANNER THAT MY COMPLAINT HAS BEEN HANDLED!!!