This number appears to be a data-mining operation. They "offer" "free" publications based on your industry. They get you to give out company info, so you can later be targeted by more spam.
Calls recieved from 402 575-5780 are from Qwest Communications also know as CenturyLink. Locations and phone numbers are:
1) Qwest Communications: 402 422-3559 add: 1314 Douglas St. Omaha NE
2) Qwest Center 402 341-1500 add: 455 N. 10th St. Omaha NE.
3) Qwest Solutions Ctr 402 697-1513 add: 3001 S. 144th St. Omaha NE.
They will NOT stop calling. It has been approx. a year. And the do not call list does not work. I would suggest sending a certified letter to cease and desist phone calls or any type of contact. And also report to the FCC. At fcc.com and call them everyday for a year and see how they like it. Imagine if they were getting a million calls a day. I doubt they would like it and i bet the calls would stop.
Good Luck.