Calls me multiple times everyday then leaves a blank voice message. When I pick up, nobody's there.

I have never answered these calls, but they have called today 3 times, yesterday 4 times, and 8 times on Wednesday (July 11th). I will try to get an answer as to who this is the next time they call; and, at the rate they call, I will most likely get a few more today.

This phone number is a company called MXenergy.  They have called me over twenty times this week and when I pick up they say nothing and hang up.  I have called them back repeatedly to get on their do not call list and yet the calls just keep on coming.  I re-registered on the national do not call list and reported them.  Hopefully that will get them off my back.