actually you do not have their number, you have a "spoofed" phone number using VOIP - voice over internet protocol scammers can show your caller ID any number they want to even your own.
720-374-8469
Country: USA
Location: Colorado (Boulder, Denver, Lakewood)
I just received a call from this number and no voice-mail message was left. Caller ID displayed 'DENVER, CO' and nothing more. Since I was not expecting a call from this area code nor from 'DENVER, CO', the call was rightfully ignored. Further internet search advises that this number has been linked to the Microsoft Windows Support Scam.
Call came from an technicial Dept windows 386 an asian sounding man was claiming I was using windows but when confronted, I told them no I'm NOT using a Windows OS but another OS, the phone when click - SCAM ALERT!