Upgraded plan to work internationally, phone does not work after arriving in the new country

[Adam]

Last week I updated my phone plan to include international coverage for when I traveled back to the US for the holidays.  When I arrived in the US, I recived a text from O2 saying that I am covered via roaming and get 120 texts and 120 minutes a day and unlimited data. Great, this is exaclty what I need.  However, even after turning on roaming on my phone, I still am unable to make calls or use data.  I am only able to use my phone with wifi at the moment.  I have tried restarting my phone multiple times hoping it would help but it did not.  I do not know how to use my phone based on the plan I bought for the purpose of traveling.  I have an iphone SE.  Any help would be gratly appreciated.

[adamtemp64 Level 65: Ultra-cool]

Try a manual network selection

https://support.apple.com/en-gb/HT201643

[MI5 Level 94: Supreme]

You need to ensure you are connected to AT&T or T-Mobile.

[liggerz87]

Could be an international block been on and I think you need to change the setting on iPhone

[jezza1234]

I have had a similar situation in the past and it turned out that customer services had not removed all of the intertnational bars on my account. Maybe worth a call or online chat with C.S