"I'm sorry, I can't support this use case so I'm blocking Jio phones" is fine. "You have to pay for this service" is fine. "Please tweet to use the service" is fine.

Saying "please tweet to use the service" and then blocking people anyway is lying. Making fun of people for doing what you asked so they can fulfill one of their needs is scummy. Telling people to Tweet to increase their chances in a lottery and then not actually doing it is also scummy.