National Health Care Association Spam on my cell phone. Computerized telemarketing costing me minutes. Sioux Falls South Dakota

My cell phone is provided by my employee, so I try to use it carefully and not give the number out without a good reason. Therefore, I was surprized to receive a computerized telemarketing call from the "National Health Care Association." Although I hung up quickly, I was curious as to how they had gotten my number. So, I searched the internet only to find that this organization has no web presence other than discriptions by various consumer protect groups. The descriptions included words like scam, obnoxious, compliants filed, and watch out for...
I still do not know how these crooks got my cell phone number.

Al
West Valley City, Utah
U.S.A.