Failure to perform requested cremation

This is a Veterinary Malpractice/Liability question. I recently had my dog put to sleep due to severe melanoma. I requested individual cremation and have been waiting for them to call me to have me pick up the ashes. I just found out yesterday that they failed to check the correct box on the cremation form. My dog was cremated with all dogs that died on that day. I will have no ashes, paw prints, etc. Do I have any legal recourse against this office for this inexcusable act?

They did breach the agreement.

If you can somehow set a figure on your loss they may agree some compensation.

How do I come up with a settlement figure?