To be able to help, I need to get more information from you.
1- Was your du SIM card working with any other device?
2- Where did you get the iPhone from?
Let me know
My phone is unlocked and I purchased it from Singapore. Now I am in Dubai and the du SIM card is not working and the message I have is: Not Registered.
please provide us with your concerned number in a private message along with your full name and date of birth for further assistance.