Same here

Called my cell, left no message.

Unknown, they called, I let it ring out and they left no message

Robot call to tell me that I qualify for a $250,000 business loan with no credit check. "Press 1 to talk to a cash specialist; Press 2 to be put on our do-not-call list." I pressed 2. (I am already on the National DNC list, so doubt they will take me off their list.) Caller ID says "Dedham MA".

If you answer the call never press "2" or any other number they tell you to press.  These spammers/scammers do not follow the DNC List and do not have one of their own.  If you press a number - that lets them know that there is another person on the other end who may be hooked into listening to their bogus sales pitch... They will never stop calling you unless you block them.  If you don't recognize a number don't pick it up.