1. The case of the complainants in brief is that they were aspiring of owning a house of their own and impressed by the advertisement claim of Opposite Party No. 1 / Builder, they had booked a flat for themselves. They were also informed by opposite party No. 1 during interaction that opposite party No. 2, HDFC, has approved the said housing project and was offering loans to the prospective home buyers. Impressed by the impressive promise made by the opposite parties, the complainants booked a flat in the housing project, called, 'Sunworld Arista' located at Sector 168, Plot No. GH - lC, Noida Expressway, Noida, Uttar Pradesh. The total consideration price of the said flat was Rs.1,36,76,375. The complainants entered into a Builder Buyer Agreement with opposite party No. 1 who was the builder on 20.2.2015 and paid a sum of Rs.11,43,381 towards the booking amount. Thereafter, they were allotted apartment No. T - 1/1502 on 15th floor of Tower - 1. On 21.2.2015, a supplementary agreement was also entered into with the opposite party No. 1. Under this supplementary agreement, the complainants were given an option to cancel the allotment of the apartment on expiry of 24 months from the