I just got a call on my cell phone. I disconnected the call before anyone could leave a message.

Automated message, claims to be with our credit card processing company with an important message.  I hung up, seeing as Chase processes all our credit cards.

This number doesnt leave messages and when you call back its disconnected

Please block this caller from my phone.  I don't know how they get my number, but I'm sure this is definitely a scam.  How can I block these calls?

800notes is not a call blocking service. You will have to do this yourself.
Go here for a detailed discussion on call blocking devices:
http://800notes.com/forum/ta-5d4e343675a5629/call-blocking-devices