My dog has a hole in her neck from defective Amazon product. Do I have a case?

I purchased an electric dog collar through Amazon a few weeks ago to help train my girlfriend's dog. The collar was very popular and had great reviews, so we bought it. It arrived fully charged but without a charger for the collar or remote, which was to be included in our purchase. We planned on only using the "vibration" and "beep" features, but tested the "shock" feature on ourselves before putting the collar on our dog. The "shock" was definitely a shock and we could only tolerate up to level 5 or 6 out of 12. The functions weren't very consistent and the buttons had to be pushed multiple times for them to work. We reached out to Amazon customer support to see what our options were. I explained the situation to the customer rep agent and they sent us a new charger claiming it would fix the problem. About a week later we came home from dinner and her dog came up to us whining and behaving weird. I took her collar off and we saw the holes in her neck where the shock prongs had been.