Even with your new explanation, I STILL don't get what you are so ticked off about!?!? If it's a friend, why don't you communicate your hurt feelings!?!? And WHO CARES who pays the vet?? If your friend pays, you can just reimburse her?? What's the big deal??

Calm down, and cool off, and you might just see that it's nothing to be ticked off about in the first place