Air India - Flight is Overbooked

what kind of excuse is this?? also giving business class tickets of a flight after * hours and the lounge access, is that really the solution to it??

there is no guidelines mentioned that while booking a flight ticket web check-in is necessary otherwise it all depends on your luck. if you are not lucky enough confirmed tickets also can't assure you seats in the booked flight due to not doing web check-in
we (me and my husband) were travelling from mumbai to ahmedabad on **th Nov **** after diwali holidays with my *.* years old son (an infant). Firstly our booked flight was at *.**pm which got delayed by * hours i.e *.**pm and was informed to us by YATRA and not by airindia. As soon as we reached the airport by *.**pm (which by the way is well advance in time than the usual ** minutes check in window for a domestic flight) we were told that the flight is overbooked as you are late and didn't do web check-in so they can't give us seats in the flight booked by us.
The solution offered was, that they will "try to" accommodate us in a *:**pm flight of Jet Airways (the affiliated airline partner). after making us wait for * long hours, we were informed, with the cliched response, "we are really sorry for the inconvenience!!" The jet Airways flight is also full. There is another airindia flight at *.**am and we will get you business class tickets with the lounge access on that flight.

we were not left with any other option but to accept this, given we had to reach ahmedabad at the very same day. But just when we thought this fiasco has come to an end our *.**am airindia flight got delayed by *.* hours. The scheduled departure was now shifted to *am. So basically we were at mumbai international airport, with an infant, for nearly ** hours for a just * hour flight, serving our punishment for not doing web check-in and choosing airindia.
this was not at all a happy diwali for us.