I am thinking,
You can try bargain with your vet. Tell her exactly how you feel (overcharge
, ineffective treatment) and ask her to revise the bill, either give you
cash refund (probably hard), or cash credit towards feature uses (more
likely). Also hint at her that if she does not negotiate, you will make your
voice heard as a consumer. Yelp reviews for one, is pretty effective,
especially for small businesses.
Try your best, but dun get too down on this. If maomao is well now, that is
a blessing. Dun feed dry food anymore, only canned, maybe try raw? Cash can
buy health, happiness, and peace of mind, then so be it.