Mode of reply to the legal notice

Dear experts, Here is my query. Myself karthik currently working in Singapore. I previously worked in a pvt company in chennai. All the empoyees had claimed excess travel allowance bill. Now company sent me a legal notice telling that I need to pay them back the said amount in 7days else they may take civil action against me. Later I have replied to my previous employer through his company mail stating that I will be paying him back with a demand of my PF account clearance. Now please advice me on this. Mail id:karthik.250788@gmail.com