Last week I ate a nutrition bar and bit into what appears to be a tiny diamond, which was in the bar. Since then one of my teeth has been very tender. I contacted the company and they took down all my information and said they will send me a self addressed envelope in which they want me to send the packaging and the tiny stone to them so they can have a look. This makes me uncomfortable as they will have the evidence and anything past that point will be my word against theirs. What should I do, should I hold onto what I have?