Hyundai Motor India — Air bags not opened, and high price for repairing

My car Hyundai creta met with an accident 1& hlf mnth ago. It was a major accident, the car flipped, and the air bags did not open. I went to the Hyundai service (khammam) Telangana and asked the same, they said as it was not a front/direct middle impact the air bags have not opened, and they gave me an estimate amount of 5lakhs(covered under insurance) of which 10% should be paid by me. Now after one mnth of inspection (the repair has not yet started btw) they are saying the engine is also damaged and another 2lkhs for the engine so the estimate is 7lkhs(under insurance) and another 20k i have to pay for the engine. Now when the engine has also damaged why the hell the air bags did not open. Now after repair how am I supposed to know the air bags are working or not.