Walmart did sell cast iron pots and pans both in-store and online. Walmart typically carries a variety of kitchenware, including cookware made from different materials, such as cast iron.
To find out if Walmart currently sells cast iron pots and pans or to check their available inventory, I recommend visiting the Walmart website or contacting your local Walmart store directly. Online retailers and other kitchenware stores may also have a wide selection of cast iron cookware if you are looking for specific brands or models.