Calls and hangs up after I answer.

Frequently calls and hangs up after answer.  Never leaves voicemail, and you can't call the number back.

Also calls from the following numbers:

608-831-0157
608-831-3709
608-831-0112
608-831-3701

These all appear to be the same source.  If you get a call from any of these numbers, do yourself a favor and either block it or add it to your phone book with the custom ringtone set to silent/none, so that you won't be bothered by it.

I have gotten calls from these numbers as well.  Never a message, and never on the other end when I answer.

608-831-3709
608-831-0112
608-831-0135

These numbers are unpublished, and blocked from calling back.