How about we start with knowing that it's not "free" as in "costs nothing to anybody", as UncleMeat has already acknowledged that it's being provided by the government through taxation, and actually address why you thin that it's bad, rather than just repeating "it's not free! it's not freeeeee!!!!" over and over again, as if we're idiots who don't understand how taxes and public funding work?
Since you're the one trying to prove that free education is bad, why don't you address those, and then if we think you're wrong, we can rebut? Rather than demanding that your interlocutor prove your own points for you.