SBSTC — conductor forced me to pay baggage charge for a minimal-sized luggage

While commuting journey from karunamoyee-durgapur on 06/11/2018 at karunamoyee depot at 9:00AM, my sister was forced to pay an undefined baggage charge of Rs. 50/- for a gift-item of nominal size that could even fit under the seat. The amt. is not the issue of complaint but the way the conductor and the staffs of karunamoyee depot charged us should be brought to notice to SBSTC management.
At first, he asked me to give 100/- for the item in cash during the journey which was clear he wanted to turn in his pocket.
There is no defined charge-list for any luggage-cost, and as such they are looting passengers in this way. On getting a hint that i was about to raise a complaint, he got scared and tried to bargain for Rs. 50/-. The luggage was a gift item for my mother which could even easily be fit in a lap, still I was maade to pay for that as per their wishes.
Even the clerk in the counter said "go wherever you want to complain. we are not bothered" and given me the 50/- ticket.
SBSTC is such a trusted company for frequent travellers like us and behaviours like this honestly lowers its fame.
There should be a defined luggage-list in SBSTC site or otherwise these staffs will continue to loot us as per their wishes.

Requesting a proper inquiry on this incident,

Saikat Mallick.
[protected].
mail: [protected]@gmail.com