Mtn is *****img my data

I am very unimpressed with the MTN at the moment. I purchased 300MB of data twice in the last 10 days and it depletes in a two to three days without me spending time on any data using apps. When I look on my phone's statistics, it does not show where my data has gone. I tested yesterday to not use any data apps to see where my data is going. I lost over 100MB in the last two days. Please can I get someone to tell me where my data is going