Trending @Capgemini; Early Release from a toxic project!! Please help

So I have put down my papers this week and the notice period is 90 days. I asked the manager for early release as I have no to minimal dependency. He is saying that it is not in his hands and it is upto the company policy and that I have to work till the lwd according to the project needs even long hours. Is there a way to get an early release guys? Seriously I hate it here and I wanna leave. I want some mental peace. I need help here. Please