Indian Railways — 3rd ac provided against 2nd ac and train getting late about 20 hr

Pnr no : [protected]
A1- 42, 44, 46
Train: 12815 nandan kanan express
(Vsu to aljn)

Train should arrived on 05-06-17 at 19:15 hr but it was arrived on 06-06-17 at 08:49 hr and reached aljn on 07-06-17 at 10:50 hr. The train late by almost 21 hr its means almost a day. We booked 2nd ac and they provided 3rd ac due to some technical problem. It is a very common problem of this particular train.