Southern Railway — Unopted upgradation

My aged parents travelled from tirunelveli to chennai on 02/09/2016 in Ananthapuri express.They booked two lower berths well before the travel. At the time of travel TTR made a change in their seats to AC coach upper berths stating that they have opted for upgradation while booking. My parents never knew about the upgradation till he mentioned about it. The form which he used for filling is old and has no option given for upgradation. My mom and dad carried all the luggages from s7 coach to ac. My father's varicose veins have gotten severe and my mom's knee pain has become bad to worse. I need a fair explanation and necessary action to our grievance.
Ticket PNR number [protected]