Harassment by collection agents.

Many years ago, I had some hand held communication radios for which I paid a monthly airtime subscription. The subscription was with Vertel. The radios were ****** and I reported it to Vertel's agent in my area, requesting the termination of the subscription. Nevertheless, they continued billing me. Eventually they handed the case over to Creditworx for collection. I started receiving calls from Creditworx, so I requested them to forward all correspondence in writing via email. On a number of occasions, I explained to Creditworx what the situation was and that if they wished, we could take the matter to court (I have copies of ALL correspondence), yet they continued to call me by phone. Each time, I mailed them back and requested for correspondence to be in writing. Recently I've received phone calls which are dropped when I answer them. I have now traced the number ***) to Creditworx.