Ola Cabs / Ani Technologies — Worst service from ola cabs

Address:	Bangalore, Karnataka
Website:	OLA

I am totally unsatisfied with ola services. At first when i requested for cab some driver information was given and he picked me started the trip, but after traveling for about 10km's one more driver's details was sent to me. I was in dilemma and called customer care. For which dumb customer care services mentioned that my previous cab was canceled and new cab is assigned, i will not get bill if i continue in same cab and was asked to change it to new cab by returning back to place from where i started.
My question which were asked to customer care: (For which i got rubbish answers)
1) how can driver details change after trip is started?
2) if this cab was canceled, how can trip start?
3) why will i not get bill (It was official trip) since it is technical problem from ola?
4) why should i change to newly assigned cab? And how after traveling 10km's?