That really sucks with a capital S! I would be a little POed as well because you would never expect a riser to break, limbs yes but a riser is almost unheard of happening. If you need a bow to get by for this season and don't want to spend a lot of money, check out the Samick Sage. 3Rivers has them for $120 plus shipping. I got one last year for a backup bow and for a cheap TD Recurve I was very impressed.
Good Luck!