Order a free SIM Activate your 48 SIM
What is the exact behaviour?
E.g. what exactly is the nature of the screen presented when you switch on?
Any error messages?
Are you sure that it's not some iPhone quirk given that Apple seem to do their best to make it difficult to use iPhones on certain networks?
You may need to contact 48 support about this:
Hope this helps.
Any update @cutiepie?