A size on every product, quick exchanges for another size, and stock shared with your web shop.
Pick the size from the product's own sizes, with stock shown for each.
Swap a pair for the next size up on the finished sale, at the same price, without a refund.
Scan the receipt, take the pair back, and refund to the card, in cash or as store credit.
Products and stock from Shopify, WooCommerce, Magento or BigCommerce, and till sales sent back as orders.
Heel bars, stretching and cleaning added to the sale with a ticket.