CELL C - BILLING YOU FOR NOTHING!

My data bundle expired, literally just got the text to confirm. 1 minute later, I check my balance & I see that it's increased by R50. Cell C are sending me a text (TO WHICH I CANT REPLY) saying the data usage is valid & that I have to provide them with my email address in order for them to provide me with the report showing my data usage. Firstly, for the life of me I cant understand why they can't send the email to my address which they clearly have on record (SINCE I'M ASKED FOR IT EVERY TIME THEY GET HOLD OF ME - FOR SECURITY PURPOSES) & secondly I fail to believe whatever bull story they make up..it's simply impossible to use that much data within a couple of seconds (not to mention whilst I'm at work in a wifi zone). This is not the first time I get these phantom amounts added to my account. Can't wait for my contract to come to an end. ******** NETWORK.