Trying to get me to switch electric companies

Multiple calls from this number, with no message.

These people chronically call, I tell them I'm on the DO NOT CALL list yet they keep calling. They also tell me I have to renew DNC annually (not true ... I'm current). I gladly reported them. BTW, try calling their number ... you can't make out the name of the company.

I didn't pick up, but I called them back at the same number and got a recording.  "Thank you for calling NexGen Energy.  If you know your agent's number, you can dial it now."

I'm guessing they're trying to get me to change my energy provider?

I called the number and spoke to an operator and asked to be put on the Do Not Call list.  Although I got a recording initially identifying the company as "NexGen Energy", the man I spoke with said that the company is North American Power, and "NexGen Energy" is the company that is "handling the accounts in my area."  He said I was getting calls about reducing my power bills, and even though I had told him at the beginning of the call that I wanted to be placed on the Do Not Call list, he launched into a sales spiel.  

I told him that I had gotten numerous calls from this number and no message was ever left on my voicemail, they just kept calling back.  He apologized and said the sales reps are supposed to leave messages, but I'm pretty sure that's a lie.  

Anyway, I am filing a complaint with the FCC.  I am already on the National Do Not Call registry.