OLD ACCOUNTS KEEP BEING PURCHASED BY DMC

THIS COMPANY HAS BEEN PURCASHING OLD DEBT THAT SHOULD BE PRESCRIBED OR ABOUT TO BE PRESCRIBED AND IS CAUSING FURTHER ISSUES WITH MY CREDIT SCORE, THERE IS NO NEED FOR THESE AND IT WOULD BE SENSIBLE TO REMOVE THESE AS LEGALLY I AM NOT OBLIGATED TO PAY THEM , THE ORIGINAL ACCOUNTS ARE OLD , LAST PAYMENTS MADE FOR ALL ARE OVER 3 YEARS AGO BUT THIS **** OF A COMPANY KEEPS BUYING THEM AND RE-ENTERING THEM TO MY CREDIT REPORT