I was looking at my Telus bills and for the past 5 months I've been billed by a third party company called Boku for $16.99. When I called TELUS they said yes third party billing can happen and yet I have NO record of them having permission to bill me. They never sent me ANY emails or any invoices... and Telus is saying I have to call this company to cancel this charge? SHADY as F I tell ya... really not impressed. This never happened while I was with Rogers. Keep an eye on your bills... I'm out over $100 for something I've never signed up for. SO irritating.
It would not matter which provider you are with. If you signed up for something in an app or someone that borrowed your phone did, the charge would have occurred regardless. Some apps/vendors that use Boku include: Netflix, Spotify, Apple, Google, Microsoft, Facebook, Sony, and Wargaming. Boku website: https://www.boku.com/
The above link has info on what Boku is, what to do if you don't recognize a charge and preventing future charges. You may want to read through it to see if it will help.