South Bengal State Transport Corporation [SBSTC] — excess ticket price

Sir,
I have boarded sbstc bus (@ 2 pm from kolkata) from kolkata on 2nd september, 2017, and when i asked the conductor for the ticket upto 11 mile (Fare rs.115), he gave me ticket upto illambazar (Rs.120). On enquiry, he told me that no ticket upto 11 mile is available in his machine ; although, on online and other bus, it's available. My question is why such system of charging higher priced ticket will be there when the fault is not of the passenger. I urge your kind attention on this matter so that it's solved at the earliest.
Thanking you,

Regards
Ankan mandal
Mobile: [protected]