What message? Where? What exactly does it say?
Do you have an active plan?
What does your My48 account dashboard say about your current membership plan status and expiry date?
Maybe you need to buy a new monthly membership plan?
When was mobile data working ok last?
Are your APN settings configured correctly?
Are incoming/outgoing calls and texts still working?
If you need to contact 48 support about this then see the links in my signature below.
