What make and model of phone is it?
Did it ever work or are you just joining 48?
Do a manual scan for networks.
Do you see 48 and can you connect to it?
Can you receive calls and send/receive texts?
What is the verbatim message that you get when you try to call?
Do outbound calls ever work?
Switch off the phone, take the SIM out, gently clean it, reinsert it, switch on and try again to see if that helps at all.
Hope this helps.
Any update?
I'm not sure that this is the same as the original issue in this thread to be honest.
Your's seems to be specifically with roaming abroad while there's nothing to indicate that this scenario applies to the original query here...
Anyway ... you seem to be using an iPhone?
If that's the case then this is most likely the cause of your problem - due to the stupid way that Apple do things:
You may have to try many times before that tip works.
It may help to toggle airplane mode on and then off and quickly try to "catch" the local network to get that tip to work.
Hope this helps.
Did that help at all?
As I said you need to keep trying and be persistent with that tip.
http://community.48months.ie/t5/Most-Popular-Questions/iPhone-abroad-issue/td-p/36862
It's due to the stupid way that Apple do things unfortunately.
Hope this helps.
Did that help at all?