Poor service

I bought airtime this morning and converted some of it to data. I checked my email and then went on Superbalist with both sites I did not stay long and I know how much it normally charges. I then went on WhatsApp (I did not watch any stories or receive anything so don’t tell me things load automatically on WhatsApp because they do not) next thing I receive back to back texts saying you now have less than 20mb, less than 10mb, less than 4,75mb, your data has been depleted, you have been paying R2 per mb since 7am. This is back to back. I had not even sent a text. I than check my airtime and it’s now R0. So clearly it was the service that sends these notifications that resulted in me losing my airtime. This happens constantly and it’s very annoying and costly. All my settings on my phone are set that there are no updates done without WiFi. Pictures and videos on my WhatsApp also require WiFi.