Do you have a Guido membership? EU roaming only works on Guido. If you have a Guido membership and calls and texts are working but data is not then check your internet settings. If the APN field has changed from 48months.liffeytelecom.com to something else then edit it, change it back to 48months.liffeytelecom.com, reboot and see if data starts working.
Hope this helps.
I am not a 48 employee so if you need to contact 48 support then use option 3 or the chat facility here.