Procedure in order to file the case of cheating against the builder

I am retired from MOD, and moved to a new place of religion importance, with the intention to settle some time. I had purchased a plot and entered an agreement, with a local builder for construction of house I have paid the complete amount of contract, but contractor cheated me with sub standard construction,even there was specifications in the agreement. The house has to be handed over after 5 months from agreement. But even after 30 months, work not completed and he opted our leaving 15% work yet to be completed. I intended to file in the district forum,and require advice pl. 1. I got estimates for rectification & left out work from a new contractor And taken required photos Whether these needs to send to erred contractor, along with notice before filling in consumer forum 2.I was staying 30 months in s pvt rented house, awaiting new house. Whether I can claim the rent under consumer act 3.whether I can continue the construction with new contractor or to wait till the verdict