Who called from 2149034450

Caller ID = "AM HEART ASSOC." Wants us to deliver envelopes to our neighbors. No, it has to be a scam.

Received a call from this telephone number. No message was left. Anonymous callback reached the American Heart Association.

American Heart Association on CID.

I have also received many persistent calls from Am Heart Assc which is what the caller ID said.  Finally answered today in hope of getting them to take me off their list.  However, a woman on the other end of the line asked if it was me and I asked who she was, then she said - oh good - glad to reach you and a message came on saying the call was being recorded for quality........ and I hung up.  I have blocked the call numbers which are:
214 305 2151
214 903 4450

How do they even get my number?  Thought lost them in the last batch of blocking.