This spam caller,....Rings 3 times and hangs up.

Yep spam. Do not answer

Keep getting calls from this phone number. Four or five times a day. Will ring once and then hang up.

It does ring once, then hangs up.  Bad idea to call them, but the area code suggested it was local and I had to verify that it wasn't important.
AUTOBOT:  "Hi this is Julie with Reward Redemption. We called you because you recently visited one of our affiliate websites.  And in appreciation we have a $100 rebate card for you redeemable at popular stores like Walmart, Best Buy, Home Depot and many more.  Press 1 now to receive your $100 rebate card.  Press 2 if you'd like to be placed on our Do Not Call list."

Rings once and hangs up. Never we answered but based on what I read here my iPhone has a block this caller feature and it's know activated