Can't send messages or calls, but can receive.

[yes1]

I can't send messages or calls, but can receive them. I tried the sim on a different phone and it worked fine. I'm using the iPhone 7 Plus and it seems like it thinks I have no credit, but I'm using one of the big bundles, so it should work. When I try calling *#5005*7672# it says: Error performing request. Unknown Error. What do I do?

[MI5 · Accepted solution]

@yes1 

Contact Apple to check the phone 

https://www.apple.com/uk/retail/geniusbar/

[yes1]

I contacted Apple and went through all of their troubleshoot steps and they said it is a problem with the carrier.

[MI5]

@yes1 

You said the SIM works in another phone so that means your account and SIM are ok.

That only leaves the phone settings if Apple are correct. 

I'd connect the phone to iTunes on your PC or Mac and take a full backup.

Then completely reset the phone.

During this process, the software will be checked for updates and also the O2 carrier file.

[yes1]

I've already done this

[MI5]

So it has to be a faulty phone @yes1