Check the APN field of your internet settings. If it has changed from 48months.liffeytelecom.com then edit it to change it back to that, reboot and see if data starts working. If it doesn't then you'll have to contact 48 support and ask them about it. See the link in my signature below.
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.