not so fly eating fly eating plant

My friends Vickie and Amy got me this plant that supposedly catches and eats flies. On its own, the darn thing doesn't do much more than collect dust and it's definitely not catching any flies. So being the caring gardner who I am, I have been catching flies on the balcony, with which I attempt to feed the plant. Depending on the size of the fly, my plant chews on the fly for a few minutes or hours and then spits it out. Over and over again.

At first I thought, maybe it didn't like flies but possibly other small insects. So I started bringing home other insects. Spiders, mosquitos and I have even considered to sacrifice the lady bug, which I caught at the soccer fields this weekend. I brought it home in an empty water bottle, carried it up the stairs and then let it fly away. Ok, I could never kill a lady bug. Not even for my pathetic not so fly eating fly eating plant.

I don't get it. Why is my basil growing fast enough to feed an Italian family of four and my fly eating plant won't even eat darn fly. Any advice...this is killing me.