Kalyani Motors — engine oil leakage problem

Address: 560076

My car met with an accident and the engine was re-assembled at kalyani motors bannerghatta branch. But i doubt the work was not done correctly and the problem of oil leakage was persistent even after 6 months of work done by them. When raised an issue they did some fix and there was no such problem for last 5 months. But the problem has occurred now. They are not taking the problem seriously. I'm fed of getting this fixed every now and then. Someone please help me to escalate this to higher level and help me get this fixed or else an alternative solution for the same.