Data Bundles depleting at lightning speed

I have a contract with Cell c for a Iphone5, its been almost 2 years that i have been having this contract with them which now seems like a lifetime because of the inconvenience i have been experiencing with them lately.<br> My data bundles get depleted at an abnormal rate, at one instance i had to recharge over 4 times with them just depleting without me even doing anything with them. I called the call centre and was referred to the technical department and the agent there assisted me to switch off all applications that he thinks might be the cause of the problem. This did not help in anyway and i ended up deleting all my Apps and switching off the cellular data completely. I asked for a data report from them to show me the exact application that is depleting my data but cell c couldnt assist still. Everytime i switch on the cellular data it just starts depleting like crazy. i now have the cellular data permanently switched off because i cannot afford to pay any amounts above my contract price. <br> <br> I am very, actually extremely frustrated cause now i cannot enjoy my phone, i might as well be using those R100 nokias you get at PEP. i am definitely not renewing my contract with them.