TCS give me legal notice for excess payment. What should i do?

TCS Mail:
SirlMa'am,

We are concerned for our clients M/s.Tata Consultancy Services Ltd., having their office address at Olympus - A, Opposite Rodas Enclave, Hiranandani Estate, Ghodbunder Road, Patlipada, Thane West - 400 607 under whose instructions we have to address to you as under:-

1. That our client offered you the post of Systems Engineer in Grade C 1. You accepted the said offer and agreed to abide with the all terms and conditions mentioned therein. Accordingly, you joined the services of our client on 30-Jan-25 and subsequently our client issued an Appointment Letter

2. That after your resignation from the services as on 03-0ct-25, and you have concluded your employment and separated from the Organization on 1O-Oct-25 our clients had inadvertently continued to remit salary to you, which amounts to Rs.38,573/- (Rupees Thirty Eight Thousand Five Hundred Seventy Three Only). You knowing the facts, failed to inform the same to our client and further failed to return the same. Instead of notifying our client about this inadvertent credit of salary to your account, you have utilized the same and failed to return the Excess Salary* to our client even after several reminders.

3. Thus, you are liable to pay the total ofRs.38,573/- (Rupees Thirty Eight Thousand Five Hundred Seventy Three Only) in lieu of Excess Salary* received by you with further interest thereon at the rate of 18% p.a. till the date of payment.

4. In view of the above mentioned circumstances, we have been instructed by our client to call upon you, which we hereby do, to pay back to our client the sum of Rs.38,S73/- (Rupees Thirty Eight Thousand Five Hundred Seventy Three Only) together with further interest thereon @ 18% p.a. within 7 days from the receipt thereof by you, failing which our client shall be constrained to initiate appropriate legal action against you, entirely at your risks, costs and consequences resulting from the legal action.

Note: 1. If you desire to settle the claim/dispute amicably you may write to corporate.settlements@tcs.com

2. *"Excess salary component may also include following components "Competency Incentive and Readiness Incentive" recovery, "Health Insurance Scheme (HIS)" recovery, Loan recovery, advance salary recovery, forex recovery, night shift allowance recovery, Recovery towards IS asset damage/Office equipment/Library Book/ID card, etc."

"In case, the said dues are already cleared by you, please share the necessary payment details with TCS".

What actually happened:
I was on leave for almost 2 months due to medical emergency. I got salary of first month, then i got blocked. when i came back, i still remain block. for 1 and a half month i came office everyday and tried to unblock myself but cant happen and also for that 1 and half month, i did not get salary. I asked for resignation and they do it in very rush and told me that i will get salary od those 1 and half month. But after full seperation, they did not provide my salary so i thought it would have been compensate for that 1 month free salary at medical leave. but then they told me that 38k is due from my end. I can not understand why and how and raised ticket in tcs alumni portal but they did not reply.

Now i got legal notice. What should i do?