How do I go about dealing with my vet clinic not having answers or replying to my questions?

I took my four month old kitten to get a routine spay surgery yesterday. They told me that when I dropped her off, they would do pre-screening and then after the surgery, they would call me at 1:30 PM. I got a call at 1:30 telling me that they had bad news she had died after administering the anesthetic. They revived her, but she then died again. They told me I had two options. I could either pay the $110 to have her cremated or I could come pick her body up and bury her myself. They never told me that there could be any complications and that it was perfectly safe procedure. I asked to see her file or have a detailed explanation of the events leading up to her death and they haven’t responded.