There is a difference between fact and theory. Evolution is a fact, the Theory of Evolution is a theory that explains the fact of evolution.<quoted text>
Then we shouldn't call it "fact" and we shouldn't teach it as "fact". It is theory and should be taught as such.
It is a fact that things fall to the ground when dropped. It is a fact that light takes about 8 minutes to get to Earth from the Sun. It is a fact that there is a tiny time delay between satellites and GPS devices. Newtonian physics is a theory that explains a lot of that, and Relativity is an even better theory that explains much more of it.
One day we might get a theory of evolution that is better than what we have today, just like we did with physics. But until that day comes we teach what we know.
What is the alternative? Teach kids nothing at all? Teach them that god did it? Fill their heads with all manner of contradictory, unsupported ideas and then expect them to know how to parse the good from the bad?