Seller not cooperating for completing further process

Hi Experts, I am purchasing a Flat in Thane. Accordingly we have registered sale deed for the same on 1st Feb 2016. Total Agreement Value is Rs. 3700000/- We have paid Rs. 165000/- as part payment before registration. The remaining part payment was to be made after registration as mentioned in the sale deed but no fixed date was mentioned. And 80% by obtaining a home loan from bank within 30 days from the date of registration. There is no clause that says that this deal will stand cancel if these 30 days is crossed over. Also we had a clause in the agreement where the seller had agreed that there is no tenancy in the flat. After registration we learned that the seller has a tenant who was staying in the flat without any rental agreement. We asked the seller to immediately vacate the flat from the tenancy so that he does not create any issues in the process. The seller initially agreed but later started demanding Rs. 50,000/- to be paid to the tenant so that he can vacate the Flat. We disagreed. We were seeking home loan for this process for which we needed some documents from the seller i.e. copy of chain of agreement (she was the 4th seller), her bank loan outstanding letter and statement, list of documents from her bank which was submitted during her loan process). Ideally our bank was going do a bank to bank transfer and settle her loan with her authority / permission. When we asked for these documents to submit to our bank for further processing she refused to give the same and also threatened us that she would not cooperate in further processing till we do not pay the tenant. We informed the secretary of the society about the same who as asked the rental agreement from her. Then she made a fake agreement with the tenant on 24th Feb 2016 i.e. after our registration. We took this matter to local police station but they refused to file a complaint of fraud against the seller and tenant stating that it is a civil matter. Also she made false charges on us that we are not ready to pay the rest of the part payment whereas we had already notified via watsup and also sent a letter stating that we are ready with the remaining 20% amount but will pay when she gives us the documents required for loan process and after removal of tenant. Now after pressure from the society she has finally agreed to remove the tenant on 20th March 2016 but we still feel she will not cooperate with us in completing the home loan process or she will delay the entire process. In this situation can we file a case against her? We also want appropriate action to be taken for creating unnecessary stress for us and delaying this process for so long. Is she delays further that we were planning to back out from this deal..In that case what can we do to get back all the payments we have done (part payment + Stamp duty Registration fees + Bank loan processing fees), compensation for physical mental stress and for the time we wasted, also for making false charges on us in front of the society and police. Please suggest whether to continue or discontinue this deal and how do we go ahead. What precautions to take so that this lady does not cheat us ahead in this process.