Yes, but they are not really worth it. About the only place to get refills is Goods to Go at the main pool. No refill stations. Plus everyone there has either the kitchenette or full kitchen, so you can stock your own refrigeration with everything you can imagine for a lot cheaper.
Back when we first went to OKW, we bought some refillable mugs, but there was a small charge to refill them. Not sure if it is the same now.