833-664-0623

I received a call from this number. Verizon identified it as SPAM so it went to voicemail. Three second recording of nothing.

Unrecognized number.  Left no message.  Blocked

Several missed calls, a few blank vm over several days. I called back, auto shattered and queued to a representative. A female answered saying “Hello?” Then immediately hung up. I called back again, it answered then immediately hung up.

Several missed calls spanning several days. when I returned the call, they have an automated answering system. It doesn’t identify the company, but it said it’s routing the call to a “representative”. A woman answered saying “Hello?” And there is heavy background noise like she’s in a busy call center, and It’s a low quality phone line.  Then she immediately hung up. I called back again, it answered similarly but instead of routing the call it immediately hung up.

Suspect this is a scam to harvest live numbers for profit

Your suspicion is incorrect nonsense. Scammers have no need to pay for "live numbers".

What good does it do when you speculate about a call and have no idea what you are talking about?

Quote:

Several missed calls spanning several days.......
.....a scam to harvest live numbers.......
.....I returned the call.......I called back again....

You called a toll free number, believing they are "harvesting live numbers" and they can see what number called them, so why would you do that since it will verify your number as a live number?
When you call a number and it rings, you know it is a live number, so why would they need to keep calling? You aren't very smart, are you?