Here's the part where most people get the wrong motion going. You're not aiming to push something down the drain. What you wish to do is create suction that will remove the obstruction. Push down securely on the plunger up until the cup is pressed versus the drain. Now, BOUNCE the plunger vigorously without pulling it off the drain. You'll hear water sloshing as the suction yanks on it. Bounce for a number of seconds - you'll feel the suction 'grabbing' at the plunger.
Firstly, work out what you want your home builder to do. You may not require a builder at all but actually need a plasterer, a tiler, a Plumber or an electrical contractor. Make sure that whoever you choose has the qual