Gujarat State Road Transport Corporation [Gsrtc] — Bus fare of surat to ankleshwar

We are daily up down by white express bus from surat to ankleshvar. But all bus get different fare some bus demand 53 rupees some demand 54 and specially aanand depot bus demand 55 rupees and all bus have different km some one have 58 km, other 59 km how it possible ? Pls informe me and do some actions other wise i will go to consumer court