I know it doesn't seem like they exist at all, but most places carry them in the company, and will request a pack or more if you ask them. I ended up just ordering from Germany, which ended up being most convenient for me. Though after some digging found the occasional UK website.
My first purchase was the most nerve wracking, as I ended up venturing to a medical complex outside of town and found a medical supply store, but they were out of my size, so they had to order it anyway. The package was so big, they just barely fit into the bag I brought. I had to catch two separate buses while walking through town to transfer. Worth it, but that's why I switched to online ordering in the UK, haha.