This calls comes from MRS Associates a dirt-bag collection agency - bottom feeders.....They also use 219 area code numbers and several others as "spoofer" numbers. So bottom line if you see a number come in you do not recognize, let it go to voice mail. If it is legit they will leave a message....that is simply a fact or they will call again and maybe after several no answers they will leave a message, though with all the recent lawsuits and fines for leaving personal information on a voice mail or with an unknown third party I doubt they will - unless desperate.
Their web site is http://www.mrsbpo.com/