Black combat boots with zipper on back

Worn, combat boots in a size 9. Boots are by the brand bamboo. Has a soft material liner as shown in photo 8. Has a zipper on the back that can be unzipped 🚨BUT BOTH BACK ZIPPERS DO STICK, they are hard to zip and unzip. 🚨 There is some damage to the zippers as seen in photos 4,14,15. I also have this boot listed in another color on my page!