Indian Railway Catering & Tourism Corporation [IRCTC] — TDR Repudiate for journey not travelled

I have booked Tatal tickets for 3 persons (Family) to travel from Kalyan to Solapur on 09.06.2023 and got confirmed tickets PNR No [protected] coach no. B5 seat nos. 10, 13, 12 by 3rd AC.
On 10.06.2023 at 18.21, I have received a message from IRCTC informing that “Allotted accommodatin in 3E instead of 3A. You are eligible for refund of difference in Fare. Indian Railway”.
Since I have got confirmed 3rd AC tickets at the time of booking and after chart preparation it downgraded to 3E, I decided to file TDR at 18.59 on 10.06.2023.
On July, 06. 2023 I have received email from [protected]@irctc.co.in informing that
The TDR filed against PNR Number [protected] with reason passenger not Travelled As Reservation Provided in Lower Class has been repudiated by system as per the Indian Railways Refund Rules.
Reason for Repudiation /rejectin : NO REFUND IS GRANTED FOR TATKAL CONFIRMED TICKET
I really dont understand when the message clearly states You are eligible for refund of difference in Fare and when I filed TDR for downgrading