You idiots need to learn the difference between a sales call and a scam. To you morons, every unwanted call is a scam. You are part of the sky is falling mentality. And you are from california...go figure.

Supposedly air duct people.  Really annoying.

I was interested in a previous poster's suggesting of buying a call-blocking phone.  I love the idea but when researching it, it looks like the maximum amount of blockable numbers is 30.  I get so many more calls, and they keep changing their numbers.  I still might consider it.  Why can't someone stop these idiots?

[***] trying to scam

Thank you for your less than eloquent reply.

Are you aware that ALL of your robo calls are ILLEGAL?  And please tell us why you call numbers that are on the DNC list?

To quote you - YES, "every unwanted call IS a scam!"  

Did it occur to you that should a home owner want duct cleaning, we would contact a local, state licensed contractor?

I would urge you to get an education so that you can possibly secure employment that does not require you're breaking federal law and annoying home owners.

you - your - you're  Please learn to speak and write in business English.

Blocking phones do block 30 calls that YOU select.  Simply press a few buttons and the offending caller is blocked until YOU unblock or delete them.  With the Uniden phone you simply press "BLOCK."   It's THAT simple!

Each call is logged into your call-blocking phone in the order received.  Older numbers are at the start of the list.  If an telemarketer changes their number, simply delete their old number and enter - by pressing a few buttons - their new number.  
Remember that this is all done simply, easily and quickly.

These phones also AUTOMATICALLY block -
UNKNOWN NUMBERS
PRIVATE NUMBERS
OUT OF AREA NUMBERS

Additionally, there are other blocking devices that can block entire area codes and hundreds of numbers along with unknown, private and out of area calls - they're quite sophisticated and cost less than $100.

I have had call blocking phones in my office and in my home for nearly 2 years and the telemarketer/scam calls have dropped to nearly ZERO.  Now days, I actually look forward to scam/telemarketer calls...If I have the time, I enjoy effing with them and keeping them on the line as long as possible.