This number is for a company called Verifacts. They gather information for collection agencies, such as your address or employment. If they're calling you, it's likely because you have a delinquent account or your telephone number is linked to someone else's delinquent account. Their web address is: http://www.skiptracers.com
To get them to stop calling you, send them a written demand to cease all correspondence pursuant to the Fair Debt Collection Practices Act. Their address is:
Verifacts, Inc.
204 1st Ave
Sterling, IL, 61081
If they ignore your demand, report them immediately to the Illinois State Attorney General and the Federal Trade Commission, and be sure to send a copy of that complaint to Verifacts.