no one gave their number to a scammer - blame the lack of security with the phone companies. You need to know that the scammers hack in to routers and switches out there and are then able to use any number in that system to dial out - they aren't just using the number they are using the lines -
You do realize they are using programs that spoof their phone number? If you call these numbers back, they will come back as an inactive number. These people are hacking into any phone company, they are simply spoofing the number.