What exactly do you mean by "topped up"?
Did you actually buy a membership plan or just cash credit?
What does your My48 account dashboard say about your current plan status?
What does your Transactions page say about your payment?
Do you have a connection to three 48 network - i.e. signal bars?
If not then if you do a manual search for networks can you see and connect to 48?
Is your phone unlocked for use on any network?
Are there any error messages on your phone?
If you need to contact 48 support about this then see the links in my signature below.
