Indian Railway Catering & Tourism Corporation [IRCTC] — They rejected my TDR although train was late for 11 hr

We have booked the train tickets of Azad Hind Exp from Nagpur to Pune for date 30th December. the train departure time from Nagpur station was 15;50.

on the date of journey we come to know that the train is late by 6 hr. So we decided to cancel our ticket & take bus instead to reach pune. So we call the IRCTC helpline number [protected] & told them to cancel our respective tickets. The person of that forum suggest us that file a TDR rather than cancelling ticket so that you will get full refund & if you cancel it you have to pay cancellation charges.
So we filled TDR on 30th December at 15;28 before actual departure time of that train. Even after filing the TDR we again confirm it from the IRCTC helpline forum. They said its filed.
On 4th Jan I got a mail from IRCTC that the TDR is repudiated ( which means rejected). On same day I asked for the reason but no reply over my mail. Even I call the helpline number which now said that the refund is solely handled by railways heads.

Anyone can check that train Azad hind exp 12130 got late almost every day from last 1 week almost by 12 to 14hr.