Hi. That's a Very good question.
Have you first went through all troubleshootings to be absolutely certain? If so, and still no luck, Contact Public Mobile. Explain to them of the circumstances, they can track your Data usage as well, and depending on the situation, a Fair resolution may be pursued.
I don't have those settings ((( When I go to Settings - Cellular - Cellular data network I can see only Personal Hotspot with APN field, Username and Passsword. And Reset Settings option - that's it, nothing more.
Apple Support advised me to contact my carrier. I already connected my iPhone to iTunes and downloaded carrier's updates. No luck.
Good news about configuring data with Iphone's, please view this link in the community to setup your iPhone. http://productioncommunity.publicmobile.ca/t5/Announcements/iPhone-Update/m-p/1610
Have a great weekend,
Never mind. It works now. Ty
Did you solve the problem with sending Pictures (MMS) over imessge? if so, what iphone are you using and which version?