Pigeon India — Pigeon gas stove , utensils turning black

We bought a pigeon 3 burner gas stove on October but after 2 to 3 days o[censored]se the flame turned orange and all the utensils are turning black with a black cast . After complaining the service centre, the technician came for the visit but the problem was not resolved .we complained again and this time they took it with them, again the problem was not solved.Now the problem is getting worse and it's unbearable, it takes lot of time and efforts to clean the black turned utensils and I feel it was a waste of money to buy a new gas instead my old one was working better.
I request for a new (proper) gas as gas is in warranty period.I seriously want to tell this, it feels I will never ever buy a pigeon product again in my life