What is wrong with my computer?

The Magsafe power adapter did not disconnect when pulled on, and the computer made a 2.5 ft fall onto the floor, with the corner connected to the power adapter hitting first. The power adapter slot was dented, and the computer worked, but ran out of battery. The apple store wanted to charge 700+ dollars to fix it, but did not know what was wrong. Following the ifixit guide, I unscrewed the computer and the insides look fine. The power adapter fits now, but there no light appears on any of the power adapters I use. What is wrong with the computer? What should I do?