Builders Warehouse - Poor quality goods

I needed a basic door handle for our storeroom door which is not used often. I purchased the Builders brand prof sa 3 lever lockset from builders greenstone. When trying to fit to the door, I had a problem with the screws to attach the handle to door. The screws for the door handle are flat head screws which are so poorly made that you cannot screw anything in no matter what screwdriver I tried. I had to find my own screws in order to attach the door handles. Not right!!. No matter the price of this set, you as builders have put your name to it and by doing this you have once more damaged the name of builders which to be fair is not great at all. I am afraid that in future I will have to look elsewhere first to purchase any home items before even contemplating builders.