*****ing my data

Telkom is enganged in *****ing my data bundles. On several occasions my data bundles have disappeared without any valid explanation and when I call the contact centre all they can tell me is "on our side the system shows that you were connected", even after I explained to them that all the while I was at work while my data was being used up and that my connection was offline. I use a wifi router and a laptop. This is thievery at its best, I just don't understand why Telkom is doing this to me after such loyalty as from me.