Harrassment via telephone prerecorded message

eWe moved into our house in Green Point last year in end May. We acquired a phone line from Telkom and since then we have been persistently harassed by a call from Nedbank computer generated message saying that we have not paid our credit card and it has been suspended, along with calls from the call centre in the evening looking for a Mrs Yvonne Detwiler. Although I am with Nedbank, all my cards are paid FULLY each month, but also I know that the previous owner of the telephone number, Mrs Detwiler was in arrears with Card Division. She was aged, and apparently moved to frail care and it is with this in mind that the problems arise. We have had countless calls from debt recovery which have since stopped after my protestations that she no longer has the telephone number , but the pre recorded messages come through thick and fast on a daily basis. Not only is this irritating but it disrupts our household from what they are doing to answer this useless message. I have complained to Monique Brits at Nedbank Card Division via email and she has kindly responded but to no avail. This is driving me mental having these constant interruptions running for the phone .