Errant international roaming charges refund

Posting on here because I read this was a way to escalate complaint.  I had a bad enough customer service experience that I'm leaving xfinity mobile but wanted to give a chance for them to change my mind.

From 7/15 to 7/20 I was traveling in Canada with my wife.  Having an unlimited plan I had read we were covered for calls, texts, and a fixed amount of high speed data while north of the border.  Additionally when we landed in Canada we received a text asking if we wanted to enroll in a Canada/Mexico data plan and to reply "Y".  We both replied Y.  The next day I received an alert I had accrued over $100 in roaming charges.  I called Xfinity and spent an hour in a parking lot getting it sorted out with an xfinity agent (To be fair the process was closer to half an hour, but a call dropped once because I was in a remote area and had to start over).  The conversation with the agent ended by being assured charges would be reversed and I was on a plan with data in Canada.  Between having an unlimited plan, opting into the Canada/Mexico data service, and sorting it on the phone with an agent I thought the problem was resolved.

The next day I received an alert that my roaming charges topped $200.  I ignored it figuring the problem was still being fixed.  Two day's later on 7/20 I got a message saying my roaming charges went over $300.  That evening after arriving back home I called xfinity back to get assurance I would not be charged these roaming fees.  In total between my wife's line and mine the charges were around $400.

The first agent I spoke with on 7/20 told me "literally the only possible way" to get these charges reversed was to upgrade a different line on our plan for $30 month.  That wasn't acceptable and I told him I needed to speak with someone else.  The second person was more helpful, acknowledged we shouldn't have been charged but couldn't help us herself and she transferred me to a third person.  After a long time waiting the third person was able to reverse charges by changing the generation of my plan which didn't change my cost.  That was a relief.  I later went back to our account to verify charges were reversed and they had been on my account but not my wife's.  So I had to call back again.  Thankfully, getting her charges changed was easier and probably only a 15 minute process.

Why would I leave if my problem was eventually resolved?  I don't mind having to sort out a mistake, but these charges were clearly errant and the conversation should have been as simple as "Sorry for the inconvenience, we'll get it fixed."  Instead it took talking to six people and multiple hours on the phone.  No apologies and for some reason the process involves me having to be on hold the whole time.  What really has me heading to the exit is having an agent say the only way I could get back the $400 I was incorrectly charged is to upgrade a line.  

Maybe I'm worth your time, maybe I'm not but ball is in your court.