No message, just hang up

No msg ... on call back got, "The number you have dialed is not a working number."

I am on the do not call register and have been several years.  At 10:35 am on 2/23/2017 my home landline telephone rang. From my caller id it showed w palm beach, florida.  I recognized this as a spam/scam type call and did not answer the phone.  Regardless the caller is in direct violation of the do not call register.  Again, the scammer/spammer telephone as shown on my caller id is "561-371-7621.  Not sure if that's an actual valid number or something else that these idiots would use!

Received a call on 02/23/17 on my landline phone. Caller ID said unknown name- 1-561-371-7621 A man stated he was calling with Windows and he wanted to walk me through how to fix my computer. Because my computer was sending error messages to their Network. So he wanted me to turn on my computer and tell him what the screen said I replied to him that it said I wasn't stupid. And was not falling for his scam he hung up on me.

Answering machine picked it up. No message. This was my first call from this number so it was not blocked...it is now.