Take them to court.Hope you have all the things they promised you in writing.If you do, get in touch with a good lawyer.Someone who is experienced with cyber law is preferable but any good lawyer is good enough.Your lawyer will mostly start by figuring out the various violations and the sections applicable.Then he may send a legal notice for which the charge will be max Rs.1000.or 1500.That will get the at indiamart sit up and take notice.If you want to file a complaint with the consumer forum, you can do that also.For that you dont even need a lawyer.Just a plain paper complaint will do.
India mart is the biggest fraud currently going around.They target people who have no technical knowledge.They loot money from them and dissappear.Stay away from them.Their time is coming to an end soon., just like the theives at Satyam computers and the frauds like Raju and his sons.
All the best.