Indian Railway Catering & Tourism Corporation [IRCTC] — tatkal ticket amount not refunded even when train is diverted

Address:

B-315, LSG GreenVille, 5th Main, Vinayaka Nagar, Hagadur, 560066

I have booked a ticket from bangalore to ballari (Pnr: [protected]) for hampi express to travel on 25th september. At the time of booking it allowed me to book to ballari.
But later the train has been diverted and it is not going to ballari.
So, i have cancelled the ticket and tried to to file tdr, but it is not giving me option to file.
Even when i contacted customer care they are just saying "no refund will be granted on cancellation of confirmed tatkal ticket."
I would agree to this if i have cancelled the ticket with my personal reason. How am i responsible if the train route is changed and when it is not going to my destination itself.
Please help me in getting my money back.