Indian Railways — railway berths

I have booked a ticket by internet for my wife having problem of osteoarthritis aged 54 years in the train 12262 howrah cstm duronto in 3rd ac and requested for lower berth for her knee problem. At the time of request 257 tickets was available in 3rd ac. Still they have rejected my request and allotted her a side upper berth ticket. I think this has done intentionally. Person in charge should have minimum humanity to allot a suitable ticket for a lady of age of 54. I am requesting to reconsider the berth allotted for my wife. Please take necessary action against humanitarian ground. My ticket details are as follows - pnr no. [protected], train 12262 howrah cstm duronto, transaction id - [protected], date & time of booking - 16.02.2018 - 12:45 hrs., berth available at the time of booking - 257, name of passenger - nupur karmakar, age - 54, sex - female
Coach no. B5, berth no. 24 (Side upper)