caleer asked for me by name and hung up.  Tried to dial and number was disconnected

We have received several calls from this number wanting to know if we wanted to lower our intertest rate on our house. They new the street name of where the house is located. They stated they were a "overflow" company helping Countrywide and other mortgage companpies make calls to help lower my interest rate. The said I had a 7.75% on my current loan (not true).  When I tried to call the number back it said it is no longer in service. This is not the first time.