Do you have an active membership plan listed on your My48 account dashboard with a non-zero mobile data allowance balance if you're not on the €12.99 unlimited data plan?
Are calls and texts working ok?
Are your APN settings configured correctly?
What happens when you try to use connected apps or web browsing?
Any error messages?
If you need to contact 48 support about this then see the links in my signature below.
