Do you have the copy of brochure/printout/ advertisement/email/internet promotion/ handout given by sales executive etc of the offer made to you?
Did you buy the plan from a dealer or direct from company office? You may make them a party, and write to them under acknowledgment, and demand reply. You may take a crowd of local influential people to them and usually this make them move at a faster speed as it can hit their business. You can also approach media.
Companies nowadays present SEF and plan offered document to customer to sign, which are to be countersigned by the competent staff of the company, and have to provide copy to customer on the spot.
Did you receive it?
If you feel that no plan offered document was signed by you and if company claims you have signed it then you may persist to supply you a certified copy. Companies are known to forge.
Do you have the complete details of all calls made by you, received by you and complaint numbers issued by CCE?
Did you escalate to Nodal Officer/Appellate Authority?
You may narrate all transactions to Nodal Officer of the company and demand the certified copy of all the documents and call to withdraw the legal notice.
You may log on to the website of the company and escalate to the MD, Company Secretary of the company as well, with a copy to the local BM of the company, and make a mention that if company does not resolve say within 7 days you shall be constrained to approach the institution of print and electronic media, Police, courts of law, regulators, social-legal-public portals at their cost and consequences. Demand a written reply.
It is always better to transact in writing under acknowledgment with companies.
You can approach Lok Adalat, consumer forum.