Indian Railway Catering & Tourism Corporation [IRCTC] — train time table changed without informing the customer

Website:

IRCTC.COM

I booked a ticket for south bihar express on date[protected]From rajendra nagar to jharsuguda) pnr no. [protected]
The time of departure was 20:25.
Earlier it was rac but today after the chart was made i received the message of confirmation of seat no. 22 coach a2. But there was no information regarding time of train. So as per the scheduled time i reached the station on time (8:15) but the train had left by then, at the counter i was informed that timing has been changed from 15th august and train had left on 19:45. But i was not informed about the changed time table!!
Please let me know who is responsible for this because in the ticket which i booked timing for departure is 20:20. I want to know if the amount will be refunded to me or not?

Kumod kr. Jha
Contact number - [protected]