Called at 4:43pm as soon as I answered it sounded like they hung up. Don't know what they want?

Did not answer or return the call.

They are trying to sell HVAC.  They constantly call over and over after I told them not to call.  They called twice today, at 430p and 550p, and based on my phone records they've called a couple times last week but either didn't leave a message or hung up.  Lame-o.  I reminded them that each call costs them $500.  They hang up before they state the name of the company.