yes they keep calling saying I owe them money

I CONTINUE TO GET REPEATED CALLS FROM THIS NUMBER THREATENING ME WITH WARRANTS AND JAIL TIME

I HAVE GOT THREAT CALLS FROM AN UNKNOW NUMBER WHICH I NEVER ANSWER BUT THEY LEAVE MESSAGE FOR ME TO CALL THIS NUMBER AN STATE THAT THEY HAVE WARRANTS AND I OWE THEM MONEY.. THIS HAS BEEN GOING ON FOR 2 YEARS.  THEY EVEN CALL MY WORK AND WE TELL THEM I NO LONGER WORK THERE BUT THEY STILL CONTINUE TO CALL.  IT GOES ON FOR ABOUT A MONTH AND THEN THEY WAIT A COUPLE O MONTHS AND START OVER AGAIN

Ive been receiving unwanted call from this # so many times, calling my work number...I finally gave him a call with my cell #. I know I shouldn't do that but I did. The officer told me I was in trouble with a debt of 550.00 which i needed to pay. THis man has a Indian accent too. Right now he is calling with a different # again with the same Indian accent. How do I get rid of him? Heeeelp!

How do I stop these calls?