We allow the appeal partly and modify the impugned order accordingly. The Complainants would be entitled to recover from the OP  the sum of Rs. 4.20 lacs with pending and future interest @ 15% from the date the respective instalments were paid, until payment, in terms of prayer (C) of the complaint. The Complainants would also be entitled to compensation of Rs. 50,000/- as originally claimed by them in the complaint and so also costs of Rs. 20,000/- considering that the complaint remained pending for a number of years, in terms of paryer (D) and (E). Both the appeals and the complaint shall accordingly stand disposed off in terms of this order.