Disable calls and SMS and use only mobile data with active SIM card
There is one hack by which you can block your incoming calls.  

Go to Settings -> Call settings -> Call forwarding
Now Click on Always forward and enable it to forward the calls to a wrong number.
This will ensure that calls will not come to you and the caller get the tone that call is being forwarded and number is wrong.

You can disable Call forwarding anytime you want.

Hope this will help.