Reply to the first question-
You can go to the consumer forum and file a consumer complian against them for the cancellation of the same as well as for the return of money.
Reply to the second question-
You should first serve him a legal notice in his phone number itself as well as in his email ids if have.
If no reply then use the same legal notice as intimation to him, and file a suit for recovery of meh in the civil court of law with interest from the date of filing the suit till its completion.
You can very well give his phone number only, and request the court to issue summons after letting his adddress recovered from the agency of government.