Mine rang once also - however, I read about a scam where people hit call back and it goes to an offshore account that then bills you hundreds of dollars for "services". Basic rule, if was important, the would leave a message.
Yes, I received a call from this number on my cell phone about 6:00 pm. Rang twice and hung up. Since I don't give out my cell phone number, and I was not on a computer, they could not have gotten my number from a website. Undoubtedly a scam.
Just got a call from this number on my cell phone. The recording said she was Julie from Reward Redemption, and that I had just visited one of their websites and I had won a $100 gift card for visiting their site. Instructed .to press 1 if I wanted to hear more, press 2 (for who knows for what, I hung up before I could listen to what pressing 2 did).
By the way, the Do Not Call law states that they are allowed to call you whenever they want to if you have already contacted them, which implies a relationship of some kind with the company or person. That means that if you call them back to find out who called, you would be listed as having contacted them, and they can call you all they want. Never call the unknown number back...it will just make it legal for them to contact you again.