Does Roadrunner Allow Phone Numbers To Be Blocked/rejected By Customers?

 We are debt-free - home, cars & credit cards are at zero but this 'law firm' (which it isn't) is one that looks up the elderly, handicapped etc & claims one owes money up to 20 years past - which is far past any legal deadlines for such attempts to collect, even if there were a debt! This a company does robo- calls which has been ringing our phone off the hook for more than 5 months - up to 6x a day despite repeated requests to STOP.  There are many lawsuits against this company for it's deceptive practices and harassment.  I need them to quit bothering us & asking to have our number removed simply resulted in MORE calls!  We want their number rejected so the harassment will stop. We don't want to change our number because it's too much hassle.