Hyundai Motor India — Major damage to gear housing due to internal breakage of bolt inside housing

Address:

Jhajjar, Haryana, 124507

I have been using hyundai motor i-10 car, 1.2 gl, magna e-3, chasis no 632344, engine no. 404099 with rc no. Rj14 ck-0485. I had send my car for clutch problem repair and gear oil lekage on 20th aug, 2016 at 9 :30 am and was promised to give it by evening +vly.
In evening i got a call that the estimate cost if increased to 2.5 times and vehicle cannot be given by evening. I visited the workshop drishti hyundai and i was really surprised to know about m8 bolt damage inside the gear housing and it had done major damage to gear housing and needs to be changed. I am forwarding some pics for it. It is really strange how can a bolt can be broken inside the housing and can damage it inside.
I believe it is a manufacturing fault or heat treatment fault and needs thorough investigation and a proper capa to avoid these types of problem in future (Photo attached.
I am also not satisified with the services provided by drishti hyundai, bhadurgarh. They provided me a car which could go up to 4 km and stopped in middle of the highway due to overheating of the engine.
I wat proper capa forwarded, got complete repair free of cost due to engine internal problem and a substitute vehicle of good condition till my car is completely repaired.