I get my supplies out of Belize City.

Island Supermarket carries Purina cat chow.

Pampered Paws usually carries some of the Iams special diet foods.

Have you checked some of the hardware stores for kitty litter? Sometime you can find unexpected stuff in the strangest places.

Complaints to the shop keepers is just a waste of time. Telling them what you would like, showing them an example and informing them where they can get the products tends to reap successful results.

If you want specialty foods it isn't really that hard to import the stuff. You want to order in some type of bulk since BAHA permits are $50 per shipment then you have duty and shipping costs, broker fees etc. Still, at least you can get exactly what you want, and it is still usually cheaper than the store will charge because obviously they need to make a profit.