Tech Mahindra — Full and Final settlement Issue and reliving letter issue

I received the the Full and Final settlement of 162000 and they added laptop recovery as well which I have already delivered it to them and same was acknowledged by the asset team on mail. However they did not reduce the amount. 2nd mail I received saying that there's been a mistake from their end and they forgot to count my remaining leaves in it. 3rd mail I received in which the laptop amount was reduced by 30k only. I have raised ticket from their portal and it shows as resolved but nobody reached out to me nor did I get any mail. I have sent mails to BHR and she says raise ticket on the portal. I have raised for the third time and it is not resolved. My current company is asking for the reliving letter which I have not received yet due to fnf issue. I am ready to pay for 45 days notice shortfall but atleast they should send me a rectified fnf for the same