[farmpony84]

there are trainers who do get problem horses to sell, but they do it on purpose, they buy them for cheap and put 30 days or even 90 days into them and sell them. but not always, sometimes they'll get a horse in and use it for their lesson program until it sells.

Your trainer sounded like she was being a bit on the nasty side though. My geuss is, you bought that horse without her input so she's mad.