Odd that they don't have it at the GF....you can walk over to the Poly and grab a case. 2nd floor shop in the GCH....short walk or take the boat (with a stop at MK). They have gallon containers of water, too. Nice little store.
If you are a Amazon Prime Member, they are now offering Amazon Prime Now in the resort area. You can order anything and it can be delivered in 1 (additional fee) or 2 hours (free).