Regarding FNF amount

Hi, I resigned from the company in Dec-15, 2014 and suffered the notice period till 1st Jan 2015 . Email has been marked to HR from my immediate reporting to do FNF , then i approched HR regarding the same they said it will be done as per the email you will get 1 month and 1 day salary plus your bonus however it will take 45 days as per company rule, i said ok .When i called them again on 15 Feb 2015 regarding FNF they said as per their calculation there is recovery coming up and i have to pay the amount to them. I said what recovery and please share your FNF calculation they denied I shared the calculation done by company accountant and they said their calculation are correct one. Now it more than 4 months i am asking for my fnf amount and they are changing their statement again and again Once they said you will get full amount and than show recovery again on my visit their HR Head said 18 days will be payout now again they change their statement now they are asking for money for which i am not liable to pay Please suggest