PROBLEM STILL NOT SOLVED

I have been having a problem with my data for the last week. I have changed nothing I do. i load data and withinn minutes without me doing anything I get a message to tell me i have under 99mb data and a few minutes later another message to tell me my data is finished. I know what i use my data for and I am not on my phone all the time. updates are done when on wifi. Furthermore I use wifi at work from Monday to Friday. Having this issue I had to make time to go Centurion mall. The assistant there was rude and unhelpful. He says i should update my software, which only came up this weekend after the data issue already started. He went on to say I must change from roaming data to Telkom only as roaming switches to MTN which charges more. My concern is that it has always been on roaming so why did i not have this problem in the last 8 months. I tell the assistant to book my phone is as I refuse to spend more on data or my new data for October kicks in and it all gets used up before i even use it, he tells me there is no point as the phone is fine. Now i still have a phone eating my data when i am not using it and Telkom cannot help me!!!!!