Tekton does not make them. Those are made in Japan by Engineer. There's also a rebranded version of those pliers for the US market under the Vampliers brand name. I have a pair of those pliers and frankly, they are a waste of money. They only work on certain types of screws. They are pretty much useless if the screw is seized. The model I have at least is too small to apply much leverage. It will only work under deal conditions. I'll be sticking with my large vice grips.
They make a bunch of different sizes. I have 4 and they work great. perhaps the one you got was too small for the screw size. the grip on the tip works so much better then a vicegrip. Even if its a button head with only a very small gripping surface it can dig in and turn the screw out.
