Phew, at least that's one thing! Well, if they want their money they will HAVE to sort it out. Things like this make me cross, I'm a bit OCD with with admin stuff!
I would be on the phone to the vets causing merry hell. Have done this a few times over the years with good effect!! I have never come across anything quite so incompetent though! It might be worth insisting on talking to one of the partners rather than the practice manager though, I find that works much better.
I would also talk to them about the future treatment of the horse. Say you want what is best for the animal, but that it shouldn't cost you more than the excess. I would be angling for them to cover the cost of treatment if the insurance won't because of their incompetence.
