They don't know what you were doing while wearing them. They don't know how long you were wearing them for. Or if you caught the heel on something.

I too wear boots (Not from there though). The boots that I wear are normally $65. (I happen to get them on sale for $25.) When I was working, I wore them to work. You stated that you wore them around 10 times. For me to wear them just 10 times that would have me ON them (not just riding in the car) for just over 100 HOURS. That was on concrete walking/standing for all that time. That is JUST at work. Not counting if I went anywhere AFTER work. That is a LOT of wear for just 10 times.

I would suggest that you see if a Shoe repair place can put the heel back on. I don't think they charge too much.