It's Consumer Sales Solutions...

"Consumer Sales Solutions (CSS) has been in the deregulated energy sales business for over nine years. In that time we have enrolled over 2 million customers into hundreds of energy programs throughout the United States and Canada. CSS operates from a 12,000 sq. ft facility located in Tampa Bay Florida with a staff of over 500 professional sales representatives who are trained specifically on the complexities of today’s energy markets."

I've received several calls from this number in the past month.  In each case, the caller (if there really is one) hangs up as soon as I answer.

I've received several calls from this number in the past month.  In each case, the caller (if there really is one) hangs up as soon as I answer. Called back and the recording says "Thank you for calling customer service", when you attempt to reach an operator, you get a voicemail again.

Received some calls from this number. they do NOT leave any messages if the answer machine picks up. If I answer the phone manually, they hang up immediately.

Luckily, I don't get calls from these guys.  Unfortunately, I get calls from the morons in Rochester who can't use a phone and end up dialing my number.  So, basically ten times a day I have to explain to these people how to use a phone and that you need to dial a 1 and then the area code when it's not the same as yours.  And if I don't answer the phone these people leave angry messages.  My voicemail also has my number so if they'd pay attention a little bit they would see they dialed the wrong number.  These people are friggin idiots in Rochester.