Poor kitty. Hope your cat gets better. Sounds like those vets are not very detailed and naybe some incompetence.
Other day I went to the Pharmacy to have a perscription filled. Handed my perscription card to the young guy behind the counter. He checked with the Pharmaicist and said it will be 10-15 minutes. I ask for my card back and he said they will hold it. I come back 15 minutes later and they lost my card. The Pharmacist saud the young guy gave it to her but now they can't find it. Of course I question them on how can they lose a card, because there are only so many places it could be behind the counter. Well...after 20 minutes and finding nothing I get an apology, and had to go through the pain-in-the-ass process to get a new card.
I concluded same situation as your vets. People not detailed or focus, and maybe some incompetence.