I am at loss for words- I should've known better t...

I am at loss for words- I should've known better than to have let the vet care for my Scout after she developed an attitude with me. Dr. Thompson said she was concerned with his depressed breathing & then gave him narcotics that made him crash. The same dose they start opiate addicts with at a methadone clinic.. of course he died. The vet continued with the rude attitude after our cat was pronounced dead. I am so mortified.