Got a call 10;30 am but all was said was good by what is th`e deal is this a scam

Just got a message from this number - They wanted the prior phone number holder for something "exteremly time sensitive" from "Brian Walker" (which seems to be code for Bill Collector" since I've talked to a "Brian Walker" about the guy before.) They wanted me to call 626-609-0299 (which I didn't).

I'm guessing the previous debt holder sold his outstanding bill to some that is too stupid to listen to the voice message.

Keeps calling our business, wasting our time. doesnt say anything. saw the number on the caller id, called it back. all it said was "if you want to be on our do not call list press 1" i did and after i kept getting calls with no number showing or it says private number. This happened several times. Sooo annoying. I have customers to contact and these phone calls are filling up all the lines! its crazy.

did not answer, they did not leave a message. Said restricted call.

Called Me.  Did not answer.  Just calling my cell.  I just ignore the calls, but would like to somehow stop the calls.