Gsrtc — for refund of ticket

Address:

Surat, Gujarat

I hv booked ticket from Surat to Ahmedabad ..bus name Nizar to Ahmedabad on 21/5/2015..seat no 16. Pnr no G9590655..in sleeper seat..they put some ordinary bus n don't inform about it I m in very difficult situation ...Can I get my refund ? How? I hv booked online ticket ..kindly give proper answer ...Ithank you