Indian Railway Catering & Tourism Corporation [IRCTC] — pnr [protected] non allotment of lower birth to senior citizens

I have booked two berths on duronto express from secunderabad to visakhapatnam for 14/08/17 (Date of booking 4/08/17) when availability shown was 250 berths. Still we were allotted upper and middle berths. I again tried on 9/08/17 for a lower birth for my wife giving the option of atleast one lower birth. The amount was debited after which a message appeared saying the the lower birth condition was not met and that if i wish i can opt put of the transaction. What ridiculous logic is this programming? After my account is debited, the site says, sorry, lower berth is not available, you can cancel the transaction! What are they doing with lower berths? If you cant allot them to senior citizens, to whom are you allotting them? Incidentally, in the ticket confirmation, only the berth numbers are shown and not whether the berths are lower, middle or upper!