Xfinity Mobile is ok in the USA. Heaven help you if you are outside the USA, must rely on your phone, and they shut down your internet mail account due to security concerns (multiple times and yes we were using a highly rated VPN service). In theory, you can change your PW online but you have 15 minutes to receive a text code to do this. We were in western Europe (Germany & France) and could not get a text within the 15 minute window to reset the PW. Long story short, it took HOURS of calls to Xfinity Mobile, numerous password resets and still our mail didn't work. And now we're stuck with international phone calls and text bills (our phones were locked and we couldn't get a SIM card - that took more phone calls to customer service despite calling BEFORE we left - to try to find a resolution.
If you call, you are like a hamster on a treadmill - waiting on hold, repeating the same information over and over, getting forwarded to someone else to talk to, then calls getting dropped and starting ALL over, etc. Despite numerous case reference numbers, you have the pleasure of repeating the same story over and over like you never spoke to them in the first place.
We are back home and have $141 worth of international data/calls. After yet another hour plus, I've been offered $60 in credit. Seriously, the most expensive SIM card was $40 for far more data than we'd ever use. And after 10+ hours of my time calling from abroad and at home to restore mail service and bill inquiries, I am so frustrated I could spit. I was told there is a new policy - no credits on international fees. I guess this means you can vote with your time and portable account. CHoose carefully! Verizon may cost more but if your time is worth $$, it may be worth it to pay a bit more.
Sounds like you had a tough time accessing Xfinity customer service outside the USA, but those reading this thread should know that not all Xfinity Mobile customers are unhappy with their international service. We travel to Europe annually, and although we try to limit our mobile data usage and use wifi we still use our phone for voice & text. We obviously try to limit phone usage.
Before we switched, we were with AT&T and a call typically costs $1/min, and a text $0.25 each. While in France & the UK in 2018 & 2019, Xfinity Moble service was fine and the cost was only $0.10/min & $0.10/text. A tenth of the cost of our former AT&T service, and no issues with connectivity.
Our additional billings for each of these 2 trips were well under $10 each.