Called and as soon as I said hello they hung up.

I am on the DNC list but it doesn't work.

The National Do Not Call List only applies to salesman. Since they aren't selling a product, they have a legal right to call you as much as they choose unfortunately.

They called me today saying that they were doing a fundraiser for
Montgomery County Professional Firefighters.  When I called my local fire station, they told me that they are not doing telephone fundraising, and that this is a scam.  They also stated a similar scam is going on in Virginia.

I also cancelled my credit card (had a brain freeze) within minutes of the call, and I reported this to the Police.  When I offered to send a check I got a story about how the processing of paper reduces the amount of the donation the firefighters actually get.  Hadn't had my second cuppa or I wouldn't gone any further.  
Lesson learned, if they don't want a check, they are not legit.  And these guys are SLICK!!!  Beware of them.

I reported them to the Montgomery County Fire Department