I have an IPhone 6S and lately my data usage has gone through the roof for no apparent reason. I have WiFi assist turned off and I have been connected to WiFi most of the time. Any downloads are prohibited from using data because I have them turned off in my settings so I don't understand why my phone is still using so much data in so little time. For example my phone was connected to WiFi and charging and yet during this time 200MB of data was used. My phone has no update notifications to show what could have caused such a large data usage. Also I received a 50% data limit warning 3 hours after the initial 200MB were used and about mins later I received another warning stating that I had used 90% of my data. Thats another 40% in 10 mins. I am not happy about this and I refuse to pay for data I am not using. I have gone through the steps to prevent this sort of thing but it is still happening. HELP!