South Bengal State Transport Corporation [SBSTC] — Unavailability of Reserved Seat

I booked online 4 seats ( 6, 7, 11, 12 ) of Asansol to Kolkata 4:30 p.m SBSTC Bus boarding from Durgapur at 5:40 p.m. Even though I reserved all the seats, Seat No.7 was not accessable to me. Upon finding this problem, I contacted the Enquiry ( [protected] ), but he did not pay heed to me. It is requested that an immediate action must be taken.