Ricky,

I'm sure there are many things about the chip you didn't mention. You probably didn't mention it's size, insert colors, inlay shape, etc. No need to, all this is easily seen in the photo of the chip. Same as whether the chip was a backup chip or not. The buyer could see what he/she was getting. I am surprised that you are even considering a partial refund after 18 months. As others have said, that is VERY generous of you.

Greg