MTN cheats at Data just like with the disappearing airtime.

I have heard about the "disappearing airtime" fault that was supposedly tracked and fixed but it now appears that similar tricks are being played with data. I purchased 1GB valid for 30 days yesterday and it had been depleted by 9am this morning. I have a Data tracker app loaded and that confirms I used less than 62mb in this period which makes sense as all I did was a few Whatsapps, emails and Facebook Lite (no videos even). Previous to this 3GB disappeared in less than 48 hours!! I have checked all settings and have no auto updates permitted. This is such a *******.