Sucking DATA even though it is on lock down

[Silentj85138]

I have had an Iphone 4s since 12-2012 and used only half a Gig a month then in March I upgraded to Iphone 5s and suck data up.  I have communicated to tech support and they have me do all these ridiculous things to where I have only three apps on my phone and nothing to be use of wifi accept for safari.  Yet I am still going over 2g a months.  I currently have cellular data off and it is still reporting data used on my phone. What do I do?

I refuse to spend more money on upgrading my plan and or new phone.  I am 90% of the time on wifi and never lose connectivity.  I see there should be no way that I am using this much data.