If you do business with a company they can call until you say otherwise. The National Do Not Call law requires it.. see point 31 here: »
www.ftc.gov/bcp/edu/pubs ··· 107.shtmThe relevent part:
If you make a specific request to that company not to call you, however, then the company may not call you, even if you have an established business relationship with that company.
(If they call, they can get fined up to $11,000 per violation.)