Jai Maa Enterprises / Tata Indicom / JustDial — Tata Indicom USB internet modem

I had asked Justdial services[protected] for Tata Indicom customer service number. Follwing which several people called me and Mr Ankit of Jai Maa Enterprises (Add Shop No 135 2nd Floor Dwarka Sec 10. Ph: [protected]/222) was one of them.
Their executive promptly visited me on the same day on 13th February and picked up all the documentation and sold me the datacard. Said that it will be activated in 24 hours. He promised that they will be available for any problems and that they were TataIndicom authorized dealers.
On 15th Feb I received a phone call from Tata Indicom verifying my details and saying it will be activated in 1 and a half hours.
Until today (18th Feb) it has not been activated. I have been repeatedly calling Mr ankit and Pravin with no avail. They are not picking up the phone. Tata people are asking me to give them a phobne number which is not written on the sim card. Rs 2650 is gone and I have not receied any service!
I shall be oblidged for some action to ensure I receive a proper and usableinternet moden from Tata Indicom.