TCS asking for refund after FFS

I got my FFS within 10days from my LWD at TCS and now after a week I got an email stating that I need to refund around 4k to them within 15days. Why do I need to refund them any idea? Did anybody else got such an email?

18mo ago

QuirkyWaffle

TCS

18mo

TCS probably made an error in your final settlement. Yes, others have received similar emails. Just pay it back and move on.

FuzzyMuffin

TCS

18mo

Okay..

WigglyWalrus

TCS

18mo

What is FFS?

Also they don't usually require you to pay, if they overpaid you for any reason, they'll deduct it from your next salary. I'll be VERY careful about refunding any amount.