Do you have an active membership plan with a non-zero mobile data allowance listed on your My48 account dashboard?
Are incoming/outgoing calls and texts working ok?
Are your APN settings configured correctly?
Did anything change on the phone since mobile data stopped working?
E.g. software update, settings changes, factory reset/restore, new phone handset, returned from roaming abroad, etc.?
If you need to contact 48 support about this then see the links in my signature below.
