My dad was in the soda pop biz for 40 years or so, so I think I'm qualified to respond.
This sounds like a
regional brand - there are a lot of regional soda pops (and other beverages) out there. Once in awhile you MIGHT find them elsewhere (like in a gourmet/unusual foods store or website) but mostly they are just distributed in that particular region.
Examples of regional beverages include Moxie, Birch Beer, Henry Weinhard, Dr. Brown's, Nehi, etc.
(BTW I can say through personal experience that Moxie is definitely an ACQUIRED taste - I sampled it once when Dad brought home a few bottles from a business convention and ewwwwwwwwwwww...)
As it turns out, I did a bit of research and found
the website for Adirondack Beverages, the manufacturer/distributor of Waist Watchers. It's primarily distributed in the northeast US - Adirondack is located in NY.
HOWEVER - you're in LUCK, because the ONE place that sells Waist Watchers outside of their regular area is - surprise! - located in North Carolina, according to their website:
HUCKLEBERRY FARM
2550 Hwy. 221 N. Business Marion, NC 28752
828-652-8857
Waist Watcher Beverages
12 Ounce Cans
Ginger Ale
Orange
Citrus Frost
Black Cherry
Raspberry Ginger Ale
Grape
Lemon Up
Caffeine Free Cola
Hopefully Marion isn't all that far from you!