called this morning at 9:34,  no one was there.  I called back and recording said the number was "unallocated"  Now blocked.  I must get 4-5 calls a day from strange numbers and telemarketers.  I am on the DNC list with all my #s.  How do they keep calling?  Other then blocking them, is there any other way to get rid of them?

Your best bet is to not answer and not call back. What they are doing is "phishing" for working numbers. If you don't know a number, look it up on Google. If it's a reputable business, the number will either be listed on here, or it won't come back to any hits like this. Otherwise, you will continue getting calls.

Also the DNC list only works for legal business. Criminals seldom follow rules.

Businesses (research groups) that do surveys over the phones do not have to follow the "do not call list" rules per say since they are not selling anything.  Really they can't call after 9, but that's any business.  You can ask politely to not call you again and they have you verify your phone number to make sure they dialed the correct number and to make sure it also gets removed from their auto-generated list.
Other than that, that's really all you can do.

they called and left no VM and number is unallocated - another scammer call

robocall from 605-546-9859 caller ID said "UNKNOWN NAME" on Saturday 06-27-15 @ 1010 AM.

was the disgusting message from Rachel from 'card member services' telling me "there is nothing wrong with my account!"
"......blah blah ......lower my interest.....blah blah blah !!!"
pressed 1 and all I got is "dead air"
.........it sure would be nice if they got dead air period.