Sounds to me like the charger socket in the laptop might have a bent pin or missing part or suchlike in the female section.
Or the charger has a bent or missing part, in the male section.
Try and fix yourself (not really easy to recommend) by seeing if you can identify which part is mishapen, and then trying to correct the shape. If you are missing a part, though, then this wont work.
Take to a local laptop repair center / shop.
Contact the manufacturer.
Not really much you can do over the internet about damaged hardware.