Engine Failed at 45000 kms

Yesterday, I was driving from Agra to Chandigarh. When reaching Noida via Yamuna Expressway, check engine warning light came up and some different sound was coming from the engine... I was having ELM327 obd adaptor, I plugged it in the obd port and connected it with my smartphone via Bluetooth. It was showing P0301 fault code. I looked in the web about the code and get to know that misfire occuring in cylinder 1 inside engine. Somehow I reached Chandigarh and get the car to service centre next day. They thought that engine need to be opened and repaired. They said that piston rings, piston, head etc. May be damaged... And the total estimate they made is 35000-40000. They said that it is not covered under warranty because the vehicle is CNG Fitted... This is very bad experience with kwid.