Cat Menace

Hello Sir , my self Dhruval Dalwadi , i am the house owner in ahmedabad , old city area , So my neighbour rears cats more than 30/40 , it all started with 1 cat which they were feeding as the time goes the population also got increased and he had cat all over his house , cat pees,poop into my balcony area many times and creating bad smell in my house , cat will easily enter into my house if i left any door balcony open , and there are many cats which in their house , we told her very politely to keep cats at your home and he told me that i am a member of some animal welfare organisation and Menka gandhi is also supports us , so i said okay because in old city people are vacating their houses and many people vacated already due to this nuisance , now there are many Male Cats they were feeding more an more , and i feel there will be more population by the next winter i live next to his house , i can't even explain what i am suffering from , i want an amicable solution because we both are neighbour more than 30 years around so we can't speak more , relation can be affected , but now i am done , my tolerance level in finished , request you to give me a best possible solution.....otherwise i will vacate my house and relocate my self into another area.