Builder Demanding More than the Contracted amount post Contract termination

I contracted a Builder to construct a G+2 on a private property with a total BOQ value of 75lacs, I had to terminate the contract midway due to the following reasons 1. Project delayed by 5 months against contracted completion date 2. Project abandoned for over 5 weeks by better co, no work and no security on the site and no response to calls or e-mail 3. No action taken for all the QA issues pointed out i.e cracks in plastering, concealed tanks fixed 4. incorrectly, cracked wooden frames and electrical conduits not placed properly 4. Inappropriate behavior and mental harassment by your team At the time of termination of the agreement, the work was only 70% completed and i had paid them 62lacs as per the payment terms agreed. As per the payment terms i had paid an excess of 3 lacs to them. When i demanded them to pay the 3 lacs i was sent an e-mail stating they have spent 82lacs on my project and i had to pay them back 20lacs to compensate their expense and i will not be able to proceed with construction with another contractor unless the builder gives me a NOC. ironically 82 lacs spent by them is more than the total BOQ value of the contract for a completed project. Its costing me more than the BOQ value now to complete the project. As per the agreement signed following is the termination clause "In the event the Agreement is terminated, the Customer shall be liable to pay such fees for work done until the date of termination and as per the payment terms agreed between the Parties" My questions How should i proceed in this case ? Do i need an NOC to commence construction ? this is not mentioned on my agreement