Kadabra isn't learning confusion?

So I have Pokemon soul silver and I put my abra in the day care because I didn't wanna raise it because it can't learn any attack moves untill it evolves, so I put it in the day care and when I got it back it was level 20, so I level it up and it evolves into a kadabra. And I thought that no matter what when it evolved it learned confusion. So it evolved and didn't learn it, so now I have a lvl 21 kadabra that only knows telaport. So any ideas to make it learn confusion or new moves.?