Keep getting calls but never leaves message. I called it right back and got message disconnected. Must be total scam

Called my cell phone while I was driving. Over and over again. Finally called while I was at home; when I answered, identified himself as "Sean" from some research company, asking if he could ask me some questions. I started to say I wanted to be taken off of their list, and he hung up on me. There is no calling them back; you get a recorded "dial the number again" message.

Supposedly a research company. Very rude, repeated calls.

Calling and hanging up

The person keeps calling and my friends said that the phone number was invalid because it's a 555 number.