This number calls me about once a week. When I answer, the caller hangs up. When I call back, I hear "This caller is not accepting calls at this time. Please try again later." The message sounds like the standard Cingular/AT&T message lady.
Finally I got a name from this company - Savon Drugs, according to the person (yes, I got a person!) who called. Now that I know it's spam marketing, I can finally add these idiots to my reject list...