The guardian doesn't quite show the internals of a traditional tap, and the plumber I usually call, couldn't come today. The new plumber says that since the drive of the screw on the tap is ruined, I'd require to buy a new tap (pic below).
I didn't believe him, and would like to confirm if the entire tap really needs to be replaced or just some washers or spindle inside? Basically, if I turn the tap in any direction, water keeps flowing. The only way to stop it is to press it hard from above and wrap insulation tape around the tap while keeping it pressed.
ps: Dad says he suspects the tap is a washerless type which might have to be replaced completely.