860-967-0878

Received a call from this number.  Voicemail said this is Sam Cook from JC Christensen & Associates a debt collector.  Please return my call at 877-618-5005.

If they left a message there is no way they can dodge the "first contact" provision.  Save the message and take a picture of the Caller ID.

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

You need to send them a certified, return receipt debt validation, cease and desist calling, or "not me" letter.  You also need to report them to the proper agencies to which I have provided links to.  Then you need to go out and get a consumer lawyer to sue them on a contingency basis (no money out of your pocket) and let them pay you for the harassment.  If everyone did these three things, these crooks would be bankrupt and we would all be the richer for it.

received a vm from a Sam Cuda saying he was a debt collector from Ultram. called on 720-924-8224 and gave the call back number as 877-618-5005

Ultram is a pain killer.  Are you sure it wasn't Alltran since that is the name this criminal organization is now going by?

Getting calls from these crooks?  Would you like to stop the calls permanently?  How about finding out which federal and state agencies to report them to?  Maybe even making them pay you for the harassment?  Well simply read and follow my post here:   https://800notes.com/Phone.aspx/1-253-341-4274#p1371599794690334753