How can you pay for bundle gigs that you never use

I receive 2 memory card for bundle gigs or airtime in March 2013. I contact cell c on the 10 of May 2013 to tell them that i don't want this anymore, they must give me the adres where I can sent it back. Customer services has read the mail, but no response, I am not a person who checks my statements thoroughly, than about 3 or 4 months back, 1of the consultants phone me to say they didnt get my premium. I was shocked. Can you believe that such a small amount of R45 you don