Ola — Ola Drivers charge extra money in Coimbatore, Tamil nadu

Everytime i book for ola auto/ cab, the driver asks for extra 20-30 Rs for every ride. This has become very common in coimbatore city. I have even tried booming with my mom’s number and the same issue happens. If we refuse to pay the extra amount, the driver is cancelling the ride and is not willing to come to the pick up location. I have faced this issue more than 10 times and it’s becoming more common nowadays. People is agreeing with OLA on the amount displayed before the booking and only if they are okay with the amount, they are proceeding to book. but these drivers are demanding for extra money everytime. This is not fare. If needed, I can even post the details even i booked for ola services and at what time. And OLA offers coupon sometimes. I was offered one recently. For 2.5 Km- 3Km, it was actually charged at around 60 Rs. But after availing the coupon it was around 25 Rs. when i gave the amount to the driver, he refused to get the money and he demanded for extra 50 Rs. This is not fair. Why do we opt for Ola cabs then ? They should agree with the amount displayed and only get that amt. they should not demand for extra money. Please resolve this issue. Due to this middle- class people are suffering a lot.