Data depletes when no internet is being used.

I'm not one to take to social media to vent my annoyance, but I felt it was necessary to o such extents in this case. Now I'm not a newbie when it comes to computers, mobile data, and conserving little data to last long periods of time. So I don't really need a generic response (which is all I've been getting from Telkom on all my calls), regarding windows update being turned of, or automatic updates on mobile phones and what not being turned off, we have been buying the 2gb +1gb data for a long time, and nothing in the settings of my devices have changed in the past few months, what has changed however is the rate at which my data bundle is depleting. In mid march I purchased the said bundle, and it was depleted within a day and half, I called and complained and Telkom said they would investigate and get back to me, but nothing was done. again about three days ago, my girlfriend bought the same bundle and within the two days the data has completely depleted. In fact, we tried to monitor the data usage, and we noticed that the data just seemed to be depleting continuously without any internet usage on any of our devices. calls haven't helped!! (***)