It's called 'caller id spoofing'. The people calling you can make any phone number show up on your caller id. They're making a number show up that charges you money if you call it and press a certain key.
At the same time they've disguised the messages on their pay by phone system as surveys. Those messages normally tell you what you're buying and how much it costs.
Check your bill for unwanted charges if you called this number back.
I just got a call from this same number on my cell. Now hardly anyone knows my cell number.... I have a Verizon cell phone... I wonder how many other people who have been called have Verizon. I'm wondering if they sold our numbers to some "company"..... how annoying.