Makemytrip - Bus booking refund

I booked a bus on behalf of my grandfather and his in law, who both are senior citizens, the bus broke down when they boarded the bus from valliyur on Oct **th at , the bus was supposed to be arriving at *AM on Oct **st, but they changed the bus from a sleeper to a normal seating bus, did not provide a refund, no customer care number to contact and complaint, my grandfather has knee pain issues, he couldn't able to sit for a long time, yet they did not arrange a proper bus until early morning * am, pathetic service from makemytrip, and they don't even have a proper website to lodge complaint reg this issue.