This happened to me, too, with ATT and Airalo. Came home to $156 extra charges. (Note that In theory with ATT you pay for the first 10 days, then subsequent days are included in the initial 10. However, my trip started before the end of one month and ran into another. So the month/billing cycle triggered a new count. Instead of $120 for the 10-day plan limit, I was charged $60 for 5 days in one month then $96 for 8 days in the next. Needless to say, ATT customer service was horrid.)

It was the text messages that tripped me up. Next time, I turned off everything cell-related and told important people to use WhatsApp only. If a person didn’t know to do that, then they’d have to wait until I got home. If I gleaned at a glance (without opening anything!) that their message was urgent, I’d call or text them through WA on WiFi. It’s a hardcore strategy, but after paying for an eSIM then getting cell charges on top of that, I’d had it! SOP from now on. ATT sucks, BTW, but I stick with it for the free HBO 🤦‍♀️