Indian Railways Catering and Tourism Corporation (IRCTC) in past improved its refund process to make it faster. Although, there had been changes in the cancellation charges as well. If a confirmed ticket is cancelled more than 48 hours before the scheduled departure of the train, flat cancellation charges of Rs 240 for AC First Class/Executive Class, Rs 200 for AC 2 Tier/First Class, Rs 180 for AC 3 Tier/AC Chair car/AC 3 Economy, Rs120 for Sleeper Class and Rs 60 for Second Class per ticket is deducted from the amount.
A passenger can file TDR if he did not travel by train he booked a ticket in. There are around 19 categories in which you can file a TDR. One of them is a failure of AC. If you have booked a ticket in any air-conditioned classes but travelled the distance without AC due to its failure, you can claim a refund by filing TDR. However, for that, you must get a certificate for same from the TTE.
Below is the list of categories in which you can file a TDR: