REFUND!!!!!!

I received my SIM card on the 3rd of February ,which I paid for obviously before they delivered (R479). On the 2nd of March they debited another 479. Now because of poor connection I canceled the service on the 25th of March. I only used it for two months. Why did you debit another R479 when the service is canceled and I was not even connected. Please refund me this is a month to month deal . They debited another R479 on the 3rd of April ,