Employer Recovery Legal Notice

Respected Lawyers, Please help on how to act on the below : I have quit my job on November 3rd 2016 after serving four months from a telecom company. I have received a call from the Hr in November 2017 urging me to pay the recovery amount of 27k as stated in the full and final settlement. As per the FNF calculation, they have added a column called recovery 22k. But, I have no idea as to what lead to the amount 22k. There is no break down. When I have questioned the HR regarding the same, HR has vaguely responded by saying it is relocation expenses. On further questioning, the HR replied that these are coats for staying in the hotel during and orientation and relocation etc. I have received a legal notice asking me to settle the amount without any breaking down on what indulged such expenses. On several instances, I have paid my own bill for hotel and vehicle transport. I have receipts of the same. Further, the appointment letter which I have signed clearly mentioned that I am only liable to 1 months basic notice period in case of quitting before 1 year. Please let me know how to about this. Many thanks