How to cancel construction agreement

I am resident in bangalore, i have given construction project of residential house to Modern Arch construction. but they have delayed the project. so i want to cancel the project for that they are asking excess money to cancellation and not letting me to give project to another engineer before cancellation. now i want to know 1. i have started my construction without cancellation of old agreement (original copy with me only). bur they are sending their boys to site for not letting my workers not to work and threathning my workers. 2.if i go to court can i get proper valuation that how much i have to pay to old conmpany for cancellation. 3.is it possible for them(old company) to get stay order on my property, will court allow that. FYI - Agreement original copy is with me only, agreement signed by me and the real owner of the property is not me. it is my brother. so between my brother and company they have no documents. i am also ready to pay amount to the company and asking 2 month time but they are not allowing. please help me