Man sorry to hear that.
I think it's kind-of stinky that they are not covering the string/cable as well since obviously the cam breakage caused any issues you are having with it. Being that it is an XT (06 model) It would be hard to say you already wore the string down to the point of needing a new one.

Good luck getting it back in time, this is a good reason to consider owning a ready to go back-up bow.