Call Center (glossary)
Telephone service facility set up to handle a large number of (usually) both inbound and outbound calls. Some firms, however, specialize only in calls that are inbound (for assistance, help, or ordering) or outbound (for sales promotion or other messages). Most telephone orders are handled by call centers and not by the manufacturers or suppliers of goods or services. (BusinessDictionary.com)
BusinessDictionary.com, s.v. "Call Center," http://www.businessdictionary.com/definition/call-center.html (accessed July 25, 2012).