I just received a phone call from "your gas company" mentioning that we were eligible for discounts we were not using. When I spoke with the representative, something seemed fishy, so I asked him whether he was with DTE, our energy supplier, or whether he was trying to sell us something. We are on the national DO NOT CALL list and are not supposed to receive sales calls. He assured me he was not trying to sell me anything--just informing me about discounts to our DTE gas bill. I let him talk for a few minutes, until it became obvious he was, in fact, trying to sell me something, at which point I asked him the name of the company he actually worked for. He said it was Just Energy, and that was the end of our conversation.
It seems to me that any company that is trying to sell you something and tries to deny that is not a company you'd want to do business with.