Said that he was from Debt Mediation Company.  He didn't say what the debt was.  I also don't have any debts that aren't accounted for or being paid.  I have great credit and plan to keep it...so, he was blocked!

Federal law (FDCPA) requires them to send you a letter (US MAIL ONLY) within 5 days of their first contact that contains their name, physical address, the creditor’s name, and the amount of the alleged debt.  It also must contains “mini-Miranda” telling you that it is an attempt to collect a debt and that all information will be used for those purposes.  The one other important thing that this letter must also have in it is that you have a right to dispute the debt within 30 days of receipt of the letter and if you do so, all collection activity must be stopped until the debt is verified.
Read up on your rights here, get template letters to send and also make a complaint at this government site:  http://www.consumerfinance.gov/

Also file a complaint with your State Attorney General's office.
List of State AG’s offices:  http://consumerfraudreporting.org/stateattorneygenerallist.php

Left a vm saying "This is Robert Thomas. We tried to deliver a parcel to your address & it was returned...". Just their way if trying to get a reaction. Not today, satan. Not today.

Returned parcel call him! Call threatened me

Got the same message from this number. Don't do anything with this message except delete it.