Movers have not paid the agreed money for the damages of goods

I got my household goods and personal car transported to Noida through Packers and Movers in February. Some of the items were damaged during transportation. The company agent surveyed the damage and offered me some amount in lieu of damages, to which I agreed. The company sent a confirmation email acknowledging the amount to me in February. Now it has been 5 months and amount has not been credited to my account. Every time I call them, they say that they have processed everything from their end and now the file is with their Finance Department and I should wait for another 15 days. I want to proceed with serving them a legal notice or any other suitable way.