Walmart Centennial on Briarwood Avenue Spark Drivers refuse to pick up orders to deliver unless they get the tip first. They live for free on Walmart premises but refuse orders without tip. There's a three hour window to add a tip but these Venezuelans using the language barrier as an excuse refuse to deliver orders on time, horrendous drivers and never answer because they do not speak English. Please tip only when they deliver to you. Otherwise they drop always at wrong address.