Found mine online. Usually it’s only two or three styles that go that high. You have to dig. Vans I found at a Vans store in a mall. It’s always a crapshoot, maybe one time in ten they’ll have anything. I always walk in whenever I’m there and just ask “what’s the biggest size you have available in store?” Usually 13 is the limit. Occasionally I find something worth buying. Usually it’s the most plain and boring shoe you can imagine, but last time I found something I actually liked.
Anything above 13 is really hard to find, I feel you.