These people call several times a week, all different times of the day
I was getting lots of these calls offering to lower my electricity bill from this phone number and others. After searching, I found a blog comment and called 866-246-7196 for a do not call service. The person said they provide this service to a small number of companies that call consumers that want to minimize complaints and save time not calling people who don't want to be called. With nothing else that worked, I gave the receiving phone number which she verified on their list and then she added my receiving phone number to the do not call list. It took almost 2 days but thereafter it did stop the calls.