I have a basic plan for my daughter that provides 100 Canada-wide minutes, 250MB shock free data and unlimited (text) messaging.

She primarily only uses her phone while on Wifi, but will sometimes use it while at a friends, walking to/from school or out and about.

When I first setup the phone we were having issues with her data being used very quickly for messaging while away from home (the rep was fantastic and explained iMessage, photos, etc is not included in basic texting so it was using data).  To rectify this, we increased her data to 5GB.  She rarely even uses much data at all, but I looked back at billings and noticed this month and 2 months ago there were charges incurred for “picture messaging”.  

I called and spoke to a rep, who informed me that using the phone away from wifi, will incur picture charges if “stickers”, pictures, etc are being used because her plan is only for (text) messaging.  I asked why the data would not be used to cover this, as that was the entire point of increasing her data amount, so that she could be able to send messages while away from Wifi.  I received a confusing and unsatisfactory response and was told to solve the problem I would have to physically turn cellular data off on her phone - which then means she can’t even use her phone when away from wifi, so I am not sure what the point of having the phone, or the data is.  I even ran this issue by a techie friend, who was just as confused as I was, and said that data should kick in to cover these messages off of wifi. 

I’d like to understand why these charges are being incurred and a reasonable way to prevent them in future that doesn’t rely on cutting off her data.