The proper local jurisdiction to file police reports would be the Charlotte-Mecklenburg Police Department
http://charmeck.org/city/charlotte/CMPD/Pages/default.aspx

You can make a report by telephone - If calling outside the Mecklenburg County, the Non-Emergency Crime Reporting: 704-336-7600

You can also make a police report online at
http://charmeck.org/city/charlotte/CMPD/Pages/ReportACrime.aspx

For at least the last year, an illegal group of debt collectors have been terrorizing consumers, their family, friends, and employees threatening to arrest the individual of an unpaid loan or other debt (their generally don't even owe). Be aware debt is a civil matter, not a criminal matter, and you can't be arrested. They threaten a warrant if the victim does not pay a sum of money by the credit card over the phone.

Some of the people they are calling do not owe a debt.  Others they are calling have already settled their debt with the organization who owns the accounts. Even if you do owe a debt, do not be deceived by the actions of this group.  Many of the accounts they are attempting to collect they do not own.  In other words, if you pay these people, that is not going to clear your debt with its rightful owner.  

Although when pressed the callers give the victim an address in Columbia South Carolina (usually a vacant lot) or Atlanta GA (often a parking lot near the bus station). They are actually out of the Charlotte North Carolina area. The scammers are using the following business names (and there are many others, and they seem to create new ones daily).  They will normally answer the call back number as ?Investigations?

Reynolds, Hill, and Associates
Berkley and Associates
Kaufmann and Associates
Sanderson Blaine & Associates
Blaine and Associates
McKenzie Reid Associates
Kennedy, Kline, & Associates
Nationwide Asset and Recovery
Piedmont Investigations and Procurement
Raffino, Garrison, & McCoy
Greenman, Schwartz & Associates
McCoy Law Group
Salem Associates
Reynolds and Associates

Here is a set of links to a variety of threads on this forum that document this group and its behavior. They include the experiences of victims as well as a former employee or two that quit within a week of finding out exactly what was going on. They also include responses from consumer advocates and people who are really criminal justice professionals advising victims of what to do

http://800notes.com/Phone.aspx/1-855-748-8367
http://800notes.com/Phone.aspx/1-855-719-1725
http://800notes.com/Phone.aspx/1-855-676-3492
http://800notes.com/Phone.aspx/1-855-805-5549
http://800notes.com/Phone.aspx/1-855-751-1084
http://800notes.com/Phone.aspx/1-855-803-2349
http://800notes.com/Phone.aspx/1-855-775-2417
http://800notes.com/Phone.aspx/1-855-775-2418
http://800notes.com/Phone.aspx/1-855-755-3417
http://800notes.com/Phone.aspx/1-855-746-3946
http://800notes.com/Phone.aspx/1-855-676-3485
http://800notes.com/Phone.aspx/1-855-966-3768
http://800notes.com/Phone.aspx/1-855-699-9749/2
http://800notes.com/Phone.aspx/1-855-966-6246
http://800notes.com/Phone.aspx/1-855-678-5437
http://800notes.com/Phone.aspx/1-855-967-0061
http://800notes.com/Phone.aspx/1-855-746-3948
http://800notes.com/Phone.aspx/1-855-791-2353
http://800notes.com/Phone.aspx/1-855-699-6246
http://800notes.com/Phone.aspx/1-855-735-8624
http://800notes.com/Phone.aspx/1-855-751-1083
http://800notes.com/Phone.aspx/1-855-736-3678/2
http://800notes.com/Phone.aspx/1-855-966-8529
http://800notes.com/Phone.aspx/1-855-967-2633
http://800notes.com/Phone.aspx/1-877-460-1576
http://800notes.com/Phone.aspx/1-888-609-3074
http://800notes.com/Phone.aspx/1-866-576-6210
http://800notes.com/Phone.aspx/1-888-601-5849
http://800notes.com/Phone.aspx/1-866-230-1283
http://800notes.com/Phone.aspx/1-877-658-0438
http://800notes.com/Phone.aspx/1-888-510-9327
http://800notes.com/Phone.aspx/1-888-509-0338
http://800notes.com/Phone.aspx/1-866-803-0755
http://800notes.com/Phone.aspx/1-888-511-0627
http://800notes.com/Phone.aspx/1-888-509-3033
http://800notes.com/Phone.aspx/1-888-509-0339
http://800notes.com/Phone.aspx/1-888-511-0631
http://800notes.com/Phone.aspx/1-866-883-2350/2
http://800notes.com/Phone.aspx/1-888-244-3381
http://800notes.com/Phone.aspx/1-888-512-0269
http://800notes.com/Phone.aspx/1-877-295-9550
http://800notes.com/Phone.aspx/1-855-966-6277
http://800notes.com/Phone.aspx/1-888-511-4248
http://800notes.com/Phone.aspx/1-877-725-5312
http://800notes.com/Phone.aspx/1-877-756-9997
http://800notes.com/Phone.aspx/1-888-512-1278
http://800notes.com/Phone.aspx/1-888-512-0531
http://800notes.com/Phone.aspx/1-888-512-0273

I just got a call from this number. The told me the same thing. They wanted me to wire one thousand dollars. Not going to happen.

Left a message on work answering machine.  Referred to the person they were looking for as a "defendant."  According to Mr. Number, this is an invalid number.  Stupid jerks.

They have been calling me looking for a family member and used vulgar language... Now I'm getting blocked calls repeatedly and they don't say anything

"Investigations Division".
This is a scam. They use intimidating tactics to scare you into thinking you may have a warrant for your arrest & that "officers" will be at your house the next day to take you to jail.
You can avoid this by simply paying a Fine (w your credit card). Don't be fooled!