I have been working for the past 2.8 years in an Indian Corporate Company for a low wage. Now I got a very good offer from another company whom also supports me with good technology. So I spoke with my manager and sent a resignation email and he accepted it. My actual notice period is 90 days. Since I need to join earlier, I asked them to relieve me earlier and I will do the buyout.
They agreed to it and asked me to serve a minimum notice period of 45 days. The manager even sent me a mail regarding the relieving date which is March 20. Now a business head with a bad mindset comes in to the story and speaks with the manager and I don't know about it. I just know he is involved.
Now my manager says the mail he sent before is just a reference and that is not a correct relieving date. HR says the same.
How can I talk with my manager to relieve me earlier?
I have a mail proof which clearly states my relieving date. But management is now trying to cover it up. I have completed 43 days so far and if they extend my notice I will lose that other offer.