South Bengal State Transport Corporation [SBSTC] — Luggage charges

Address:

Asansol.b.c. college

Dear concern
It's my painful duty to inform you that my two known person travel in sbstc bus from Asansol to barddhaman. They are going for some carpentry work. They borrowed a luggage which was full of their garments and tools.at the time of boarding the conductor refused to take the luggage and demanding the some of Rs 100/- extra.
We pay some of Rs 100/- and asking for luggage tickets.the tickets details is attached..
In this circumstances I just want to know is this fair enough?if sbstc charges extra amount for luggage then why not mentioned at the time of online ticket purchase? apart from that the behaviour of the conductor is not acceptable.the tickets are online purchase details also attached as documents.