I stayed at Windsor Palms last year and was told there was a Wal Mart on 27 but never found it. I realized after I got home that I went left onto 27 instead of right.
According to this map, http://www.thedibb.co.uk/villa/map.htm you would take a left onto 192 and follow it down to the end where it meets up with 27. Take a right onto 27 and Wal Mart should be right down there.
Someone else can probably verify this.