What does your online account say about your membership status, expiry date and calls/texts/data/credit balances?
Is this your first membership? If so is your phone unlocked? If not then I presume that calls etc. worked before?
http://community.48months.ie/t5/Most-Popular-Questions/How-to-unlock-your-phone/m-p/2#U2
Any chance you were barred for the remainder of your previous membership for breaching the fair usage limits and need to wait for that to expire and then ask 48 to lift the ban?
http://48months.ie/boiler-plate/terms#18
Any chance you have an existing membership with time left to run? If so then buying a new membership will not prematurely end that one and start a new one. The existing one must run its course first and the newly purchased membership will "stack" to kick in when that happens.
If none of this helps then you should log a support request to ask 48 to assist you:
http://help.48months.ie/requests/new
Hope this helps.
