Harrassment by Shapiro Shaik Defries & Associates Law Firm

I have for the last year and a half been harassed by this company for outstanding debt even though I have spoken to various of their agents on numerous occasions and cannot remember the number of times that I had sent them a copy of the Discovery themselves confirming that there are absolutely no outstanding amounts due to them. I have even sent the actual email received from discovery but they just keep on phoning and phoning me. Their agents are extremely rude and unpleasant.