Ugh that's the worst feeling. I had the same thing happen with a cheap tool. I only use the park tool BBT-now, it's way more solid. The extra money hurts up front but it hasn't failed me yet. Those universal ones just don't grab enough material on the splines.
Honestly, sometimes you just get a bottom bracket that's been cross-threaded or installed with a gorilla's strength from the factory. That hidden damage can make any tool slip, even a good one. It's not always the tool's fault like dixon.nathan said, but a universal one has no margin for error when the part itself is messed up. You can't see that problem until you're already trying to turn it. That's why a lot of shops have a sacrificial cheap tool for the really stuck ones, to feel it out first. Ruining a customer's part with a new tool is just a special kind of frustration.