DATA VANISHING SUDDENLY WITH NO EXPLANATION

This is scary. My data reboots on the 17th of every month and today is the 5th. I received an sms yesterday (4th October) that my data is depleted? Seriously? Something is going on. All MTN users need to stand against this. You go into MTN and they always reason with "Its your updates. Or it is your phone" Hogwash! I have data Saver on. My apps are all restricted for Wifi Only. I work in a Wifi Zone and my house is a Wifi Zone as well, So how is my Data finishing well before the new month kicks in? Explain? (@Mtn)