calls twice a day every day; leaves no message.

Stop calling me

I can "hear" your frustration but you must realize that 800 notes is a user driven forum for discussing phone calls from unknown or suspicious callers.  No one at 800 notes called you nor is it likely that the caller will come to this web site, read your post, know who you are, know your number and stop calling you.  Think about getting a call blocker or downloading a call blocking app for your cell.  You can control who has access to you via phone.  Here's the 800 notes forums on call blockers.  Take a look at it.  There's lots of good advice on the different types and brands.
http://800notes.com/nb/search.aspx?q=call+blockers

Keeps calling. No one on other end. Dont know anyone in Maryland. Scam.

They've been calling for about a week, picked up finally to see if it was actually important. After a few moments a static silence an operator came on saying it was a Debt Relief company.