Refund Of Purchase Price With Interest

About five years back I purchased a few plots from Unicare Developers Delhi. Land situated in Mathura (UP). For resale purposes with one condition to buy them back by the company at double after six years from the date of final payment. In the sale Boucher as well as in allotment letters the company gave in writing that water, sewer, roads, and electricity will be provided by the company along with other lucrative offers such as parks, commercial places, and others. About five years have passed but no development has done so far and there is no sign also that something will be done in near future.because of no development no customer is reaching there to buy them hence my ultimate purpose is going to defeat and I feel that even in next ten year it will be difficult to realize money which I have invested apart from interest on it. In between some heart, the problem has developed to me and I have become short of money hence I wrote to the company to refund my money with interest but they have not even acknowledged my mail.