Evacuation of tenant from commercial property

Dear Sir, I am writing this query based on mere frustration and anxeity. Please give us a valuable suggestion to overcome this. My father (now aged 70 yrs) own a commercial property in chennai which we rented out to a tea shop owner who was running the businesss since the year 2010. Two years back(2015), the tenant(shop owner) died due to physical illness. After his death, his brother in law requested my father stating his family situation and asked him to allow to run the shop by him(brotherinlaw) though the agreement was still with the shop owner who died. Considering his poor family situation, my father agreed to run the business. After a few months, my father observed that he is not maintaining the building. Hence my father gave a 3 months written notice in a white paper to vacate the premises. The shop owner also agreed and signed the notice. Suddenly at the end of the 3rd month, he filed a fabricated case on my father in the sessions court that he is threatening to kill him. After seeing the summon, my father filed a counter petition in the same sessions court and now the case is being run close to two years in the court. Since after the death of the original shop owner, his brother in law is not even paying rent regularly. The position being this, a week back(Last June 2017) he started to alter our shop without informing us and the court. When asked about this, he says "I am doing this based on the instruction from my lawyer. You can do whatever you want. You can go and complain wherever you want". Then we complained this situation in the local police station and the CSR has been filed. But the police didn't take any action so far. The sad part is Our lawyer is not co-operating with us. We don't have faith in him. He is deceiving us. He has not attended any hearing in the court so far in the last 2 years since the case has started. So far he got his fees for nearly 40k. My parents are very old aged. This is the only source of income for them. Now they are in the state of mental depression. Now they are physically tired in stepping in and stepping out of the court campus every month. They don't know what to do. We asked our lawyer to give back the case papers to us and asked him to sign the waqalat so that we will appoint some other lawyer since we don't have faith in him.Now he is refusing to sign the waqalat. Please suggest us a very good honest and expert civil lawyer in chennai who will close this case in our favor. Thanks and Regards, RAJAN