Missing airtime and data

I recharged my number with R55 bought Data 100MB for R29 I did not use my phone within 5-10mins the data &airtime was finished I went to a Vodacom shop in Sandton to enquire where my airtime was going to the Tech guy check my phone to see if they were any apps running on my phone nothing was running only my WhatsApp and find my phone apps were open to phone data. Even checked to see if I had subscribed to anything . there was nothing , he referred to another consultant check to see if I had made any calls. which there was nothing . they gave me a number to ***6 . after I called that number they told me that on they're side it shows that I was on the internet. I did not use my phone at all and I asked how can I be on the internet when the apps that use the internet are off and this is not the first time my airtime just disappearing the whole weekend my airtime has been vanishing . but now its too much Vodacom cant keep on blaming my phone because they said smart phones use the internet .I went to a Vodacom shop during working hours to enquire out of concern and I cant be doing that just for fun only to call Vodacom and have a consulate imply am lying .