Volkswagen India — Engine issue

I have Volkswagen polo Car no. RJ14CZ7177.
15 days back it was showing engine light. I talked to the service center they told me to bring the car by towing.
I towed the car after that they charged me around 1280 for services. And engine light is gone. But in just 2 days i was away in outskirts of city it comes again. I called to the service center they told me not to drive the car and bring back to the service center. Hardly i managed and get back to my home after towing my car. After requesting they provided the person for home visit. After that they have given the estimate of 42000.
I am a middle class person how can i spend money again and again . Volkswagen car services are also costly. In month of December 2020 i get my car service done under a package of 15000.
I can't spend huge amount of money in cars.
And car only runs around just 38800km.
I purchased in August 2015 no doubt car is old but how can one spend 42000 on technical fault. And what is the guarantee that engine will not occur any fault in coming days.

I have requested service center to give discount on this because its not my fault. It's something technical fault.
I can assure you that engine is not harmed till date or ever been touched by any outsider or opened. What the service center offers me is 20% off on labour charges i.e around rs400. Is it any kind of joke ?
Service center name :- Tanya car pvt ltd Jaipur Rajasthan.
Please help me in this to fix the issue.

Regards
Saurabh Sardana.