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:
2550 Hwy. 221 N. Business Marion, NC 28752
Waist Watcher Beverages
12 Ounce Cans
Raspberry Ginger Ale
Caffeine Free Cola
Hopefully Marion isn't all that far from you!