Getting several calls from this number. I never answer, and they leave no message. Caller ID says Mindy Melemed

Company is promoting energy efficiency and cutting cost of electric bill. If you are a permanent resident, own your own home and do not have it on the sales market or in foreclosure, they want to send a rep down to spend 20 minutes evaluating your energy use. I inquired further about the "program" and was told it involves solar power. They will probably tell you how you can purchase solar panels and get a break on your taxes and power bill. Not a terrible thing, just something I am not in the market for at this time. The people I spoke with were very polite. They were not pushy or deceptive.

I've seen this number on the caller I.D. every day for several days in a row.  They never leave a message.  I have no interest in whatever they are selling.

I answer these calls, and am very ill.  But no one responds, so I HANG UP.  How do I stop them from calling.