No service after roaming and returning to UK - SOLVED
I am posting this in case it is helpful to someone. I have just had this issue resolved by second line tech support in literally 2 minutes flat, after having my time wasted for the last week by customer services who, amongst other duff advice, sent me out a new SIM card unnecessarily and kept telling me to wait another 24 hours and promising it would work...
On iPhone 12 (i'm sure it is similar on other models) go to Settings > Mobile data > SIM applications > Roaming > select mode > manual > national.
This instantaneously fixed the issue and I had service again! Apparently if I go abroad again I may need to set the roaming mode to 'automatic' or 'manual: international'
Re: No service after roaming and returning to UK - SOLVED
I suspect it must be something to do with the way the customer service staff are managed and incentivised. If they close a call the issue is temporarily ‘solved’ in the sense that the customer hangs up and waits another day or two without calling back.
It’s not especially in the interest of the agents to fix the problem either, as the more times people call back the more work it generates for them, so they need more call centre staff and they get more work.
And there is no human interest in getting the phone working as they never speak to the same customer a second time, when the customer inevitably calls back when the useless advice inevitably fails.
It’s not like going to your doctor or a plumber who you will keep going to until te problem is fixed - these guys have an interest in getting you fixed and stop harassing them!