trying to collect prescribed debt

I am constantly being harassed by a company called MBDCS or Capital Debt Recovery to make payment or arrangement on a jet account which has prescribed years ago. I have told them on no less than 4 occasions that the account has prescribed but they continue to harass me via text message to make payment. Yesterday ( 14 January 206) I again called them and spoke to Mbali Ngubeni and told her in no uncertain terms that the account had prescribed and I consider their constant text messages to be harassment and a violation of the National Credit Act but yet the text messages continue. Should they persist then I will lodge a complaint with the NCR and possibly institute civil action for harassment.