Gujarat State Road Transport Corporation [GSRTC] — very risky bus allotted in long route

Address:

Segvi vadfaliya opp. Sarvodaya high school, Valsad, Gujarat, 396001

I travelled through umargam ambaji bus on 28.07.2019.
Psngrname: parimal patel
Tripcode: 1745umrgamjsl30
Pnrno: g28743038
Seatno: 21
When bus reached 8 to 10 km from valsad bus driver said bus breakdown. And i have teavelled by 4 different buses to reach ambaji. It was take 15 hours.
On second day return journey same bus ambaji to valsad
Psngrname: parimal patel
Tripcode: 1745amjumrgslp1
Pnrno: g28747153
Seatno: 3
Bus failure by 5 km after departure.
Thanks to driver and conductor they provide me another sleeper bus.
Now my question is why gsrtc use fail bus for such around 600 km long journey.
And one thing is clear that gsrtc routine staff also aware about the bus condition.
When i ask they said that this is old bus transferred from another depot.
Now public safety is tottaly niglect by depot manager in this case.
Please provide new bus for umargam ambaji route.
I want confimation letter from gsrtc that this bus will not use for further trip for passengers safety.