Kpn Travels — no care for customers

Had a pathetic experience with kpn on 05-aug-2018 in bus from chennai to ooty, ac sleeper. I had booked tickets for my parents and helped them board at perungalathur at 9 pm. The bus was on time at 9 pm. After they boarded i left to my house. When i called them at 11 pm, i got a shocking response from my dad that the bus took off when they had got down at hotel balaji bhaavan at sriperumputhur after informing the driver for dinner. I called the driver and his response was, we counted the bus and the bus was full with 26 people and already two people are present in the allocated seat. How on earth will the bus be full when two persons have got down. After severe yelling at my end and also by the restaurant staff who had helped my parents, they turned the bus back again to the hotel and they picked my parents up after half an hour. With all the travels i have done in various travels (Ybm, parveen, kallada even setc) this is the first time i encountered such a pathetic service. On getting into the bus my dad yelled at the drived and his assistant and their response was, if the curtain provided in the bus is closed we will not open and see if the person is present or not. This is the first time i hear such response because everytime the bus stops for rest, the assistant of the bus will open the curtain and see if all have boarded or not in other bus opertators and only then they will start the bus. What if they got down in a stranded area? Will the operator be responsible for any mishap? This will probably be my last trip with kpn. Very bad and no concern for customers.