WHERE IS MY DATA??????????

Trying to figure out if someone can explain how it is possible to have used up 11GB of data between my monthly wifi and cell contract in 3 DAYS since 1 Sep, when I have hardly used it for anything and that entire amount of data usually sees me through an entire MONTH?? I call Cell C's call center and get told I have to wait for the end of the month to see what sucked up my data, not to mention I have been charged out of bundle rates which has now disabled my outgoing calls - utter, utter bull! I am a paying contract customer that deserves to know where my data is, and get it back as well as NOT be surcharged out of bundle rates. CAN SOMEONE SORT THIS OUT, Cell C??????????? Vodacom at least pays their customers back for this sort of thing, not to mention your customer's posts on your page seems to contain many complaints about the same thing! I am fuming.