My builder is refusing to return my advance amount of rs 4l after 7 years. what rera laws apply here

Here is our letter to the Builder Dear Sir: We had paid Rs 1.0L in advance towards the booking of Villament B20 203 at Brindavan Serenity. During subsequent visits to the Brindavan Serenity site, we were informed by your officers at the site that the project was postponed/canceled in 2017-2018. We have not received a single letter from you regarding the refund of the above. For a company of your reputation, these are not sound business practices. In your interview Despite repeated requests, letters, visits and phone calls to your offices, we have not received the refund of Rs 1.7L (Rupees one lakh plus interest of 10% per year based on RERA rules - bank interest plus 2% penalty) due for the past seven years. We have tried to contact your Administrative officer Mr. Aloke Kumar who has refused to meet us. As per RERA rules, Zuari Infraworld is bound to refund the amount within 45 days of cancellation of the booking by the builder. On the advice of our real estate lawyer, we were informed to provide this letter to you. In the event we do not receive the cheque of Rs 1.7L (Rs 1.0L plus 0.7L interest) within 15 days (Mar 1st 2023) of this letter, the following actions will take place: A formal complaint will be lodged with RERA Karnataka by our lawyer A Consumer Complaints Case will be registered against Zuari Infraworld. All legal costs will be to your account We have been extremely patient with you and you have had the benefit of our money for the past seven years. Please do the right thing and arrange for an immediate refund of the amount due. Please take this as our formal notice pending legal action. Yours sincerely,