Provided Lower Quality Service and refused to refund excess charges already charged

Location/place: Pune

Name of company/service: MSRTC, Bus Service

Maharashtra State Transports sent and ran ordinary bus instead of Semiluxary bus (Service Route: Pune to Pandharpur Via Malshiras) and conductor and pune bus stand controller (Swargate office) refused to return difference of charges excess for semi luxary bus because the ticket was booked through E-Ticket Booking (using web site).
Please suggest, is there any way to handle such situation