Tamil Nadu State Transport Corporation [TNSTC] — misrepresentation and excess charged

I am travelling from chennai to mettupalayam in setc. (21//12/2019) while booking they said classic bus has rest room facility and only because of that i booked this bus. There were two buses on this date ome classic (With restroom boarding at cmbt 6.00pm) another ultra deluxe (7 pm at cmbt) charge ddifference is rs.200 excess in classic due to restroom facility and travel time is also 45 mins more than ultra deluxe. I preferred this only due to rest room facility. However they sent normal ultra deluxe bus without any such facility