Our front door recently has inside door handle knob not ab lkk e to turn to eject the lock button, when we want to get out of the house. Had to struggle in a 'breaking' strength to turn it hard in order to release the button and open door. From outside, no problem to unlock button with key. Only inside button is the problem.
Community manager's note: Check out How to replace a door knob for expert advice.

What should we do? Hope no need to replace it. If replacing door knob, would Bunnings be able to cut key hole of new door knob to fit our master key? See photo.