Inlaws Harassing and stealing the happiness of our family

We are happily married since late 2015 but off lately my in-laws are trying to steal our happiness and mentally harressing myself and wife to an extent that we don't speak to each other for days. This is becoming a daily routine and I'm getting really frustrated with this kind of weird behaviour from my in laws. We both have tried to talk through this very politely but they are not ready to sit among us to talk about anything & strongly believe that they have done nothing wrong this far. I don't know why they are upset with me - havent asked for any gifts or taken a single rupee during marriage though they brag about giving luxury items which everyone in our family & relatives (both sides) know is not true at all and yet how they treat me and my parents badly. Infact they have stopped respecting me and my parents which I don't like & looking for legal advice on how to stop this nusiance with immediate effect - personally I want to sort this among family but that doesn't work even after multiple attempts so I've left out with no more options than to take legal consuel. I look forward to hear from you !