If I were in your shoes, I would call the office and leave a message for the vet to call you back today. Ask him if he in fact examined your cat. (I'm pretty sure it's illegal to charge for an exam fee and not do an exam.) Ask him if the incision is infected and if she needs antibiotics. I've never heard of taking a cat to be seen by a vet and not being given an itemization of what was done, and what the diagnosis was. I've also never had a vet examine one of my cats without me being present.