Recovery of advance paid my me

During our recent trip to Goa, we were approached by agents of a holiday travel company who gave a presentation of a 'promotional' package where one has to make a one time payment (3.25 lacs) and subsequent bi-annual installments of 'maintenance fee' (~28,000/-) for 30 years. By making bi-annual payments one gets points which can be used to purchase stay (in a particular category) for one week in any of the properties owned by the company or their affiliates. We found the package interesting and wanted a few days to think it over. But the representatives of the company told us that the promotional offer is valid only for the day, it being their 22nd anniversary etc.. Eventually to avail the so called promotional offer we signed the offer and some contract forms. Now we realize that the package is not good for us and we want our money to be refunded. Is that possible and how?