What exactly isn't working?
Do you have a connection to the 48 network - i.e. signal bars?
If not then if you do a manual search for networks can you see and connect to 48?
If you have a network connection then does anything work?
Incoming/outgoing calls, incoming/outgoing texts, mobile data?
Any error messages,
Can you try your SIM in another unlocked phone?
If you need a replacement then see here:
If you need to contact 48 support about this then see the links in my signature below.
