Why are you overcharging me?

YOU PEOPLE HAVE A NERVE!!!<br> <br> I SIGNED UP FOR THE R569 OR SOMETHING (BUT LESS THAN R600) BUT YOU PEOPLE CHARGE ME ALMOST A R1000 BUCKS EVERY MONTH? YOUR SIM CARD THAT I HAD DONE A SWIM SWAP FOR IS NOT WORKING BECAUSE I USED MY MOTHER'S SIM CARD IS WORKING ON MY PHONE.<br> <br> TELL ME PLEASE WHEN DID WE AGREE THAT THE BILL WILL BE IN EXCESS OF A R900. I HAVEN'T USED THIS PHONE FOR ALMOST A MONTH TELL ME HOW YOU GOT TO R900! INCLUDING THE PREVIOUS MONTHS' ONE OR YOU PEOPLE MUST COME AND FETCH THIS PHONE AND CANCEL MY CONTRACT BECAUSE THIS IS NOT WHAT I AGREED UPON WHEN I TOOK UP THIS CONTRACT.<br> <br> A BIG NO! SIES