Air India — change in flight and not being informed

We were scheduled to fly from amritsar to delhi on wednesday 21 february at 2.45pm on flight no ai 462. When we turned up at the airport we were told the flight had been changed and this flight is now going to birmingham in uk and the amritsar to delhi flight had been bought forward to earlier in the delay but were not informed and the air india staff admitted as much. They then arranged for us to fly on the next flight which was at 7.20pm so we had to wait in the airport for 5hrs.in addition, we had booked the holiday inn in delhi (At a cost of 11, 648 rupees) but did not get there until 10.30pm (When we should have been there for 4.30pm) and had to leave at 5am the next day for our flight to london.