Got a call, they hung up. Called back and it says no agents are available at this time.

They have called three times....all times no one actually answers when you do.  The third time I heard a call center in the background but no one speaking on the phone.  I called back the second and third time and they say there is no one available to answer so leave a message.  The second and third times I have requested they stop calling as they are wasting my time and if there is a fourth call I will report it to the FTC