iPad Pro network error.

I've been using new iPad pro (cellular+wifi) from few months.

But all on a sudden this device network doesn’t work!

I reset all network settings but still there is a problem of connecting device network.

After installing a sim card the network stay for 3 or 4 seconds then again it turn to no network service.

There is a message in Setting>General>About>Network (PHONE NOT ALLOWED).

Is it for any technical problem?