Air India — About flight services

Worst experience at Air India flight today...
My flight is scheduled to depart at 5:00 PM but yesterday i got msg that flight has been rescheduled by airlines at 5:25 PM... I reached the airport by 4:00 PM n when i asked the crew person for the boardin status, he asked me to stand in a queue n wait for my turn.. At 4:15 i again asked, then he said the same but at 4:30 when i asked they said u r late n boardin is clossed for the flight.. Totally disappointed...
Later, after so much of argument they said that they will give me a seat in 6:00 PM flight but then also no one is willin to give me boardin pass for it n some of them also dont knw about the reschedulment of the flight.
So, i suggest all not to travel by air india as they always delayed the flight n they hired worst employees over there.