Universal Travels — misleading information and refusing to cancel the ticket

Hi,

I booked a ticket with this travels company for travelling from chennai to pondicherry on 16th february, 2019. When i booked the bus was scania ac bus, later when i checked today i could see, they have changed it to a non ac bus.
And in the scania bus, my booked seat is showing free now.

When i called to their customer care number, they did not provide any proper information and when i asked to cancel it, there was no proper response.in this case, i should get a full refund. I am attaching here the ticket, i took a print out on the date of booking itself. This is a complete cheating. Please take appropriate step.

Pnr is - uni2525130