Carol, your avatar is trippy...mesmerizing even, but maybe I'm just a cat person. Anyway, I buy my gas (straight argon for TIG) from Airgas, nee National Welders, and have always had good service. They have a store on Capital Blvd at the 401 split, and one down a back road near RDU- I'm sure there's more.
BFPE in Clayton also does it. They may be cheaper. The fill fire extinguishers but also fill Co2 tanks.