Thanks for using the forums to get this issue with your mobile services looked into whilst you're abroad, I am sorry if this has been causing some frustration. I would be more than happy to look into this for you. I'll need to ask a few questions to get an understanding your your issue.
Can you please answer these for me -
Do you receive an error message when you try to call/text?
Can you try rebooting your handset to see if this resolves the issue?
Do you have access to WIFI where you are staying? If not, do you have roaming activated on your handset? (Please be aware there may be charges if this is switched on)
Do you have a friend or family member who can lend you their handset? If yes, please try swapping the SIM into their phone to see if the issue still occurs.