I have received calls from this number every day this week. When I pick up and say my greeting, no one is there and it just hangs up. I decided to call the number back today to see if anyone would answer. I got a recording that said it was a Subscription Processing Center. They "process renewals for free trade-specific journals."

At the end of the recording, you are given three options...
1. Update your subscription info
2. Do not renew your subscription
3. Place your number on their Do-Not-Call list

I chose option 2, called back, and chose option 8.