Wrong contact details

I, unfortunately suffered a "stroke"6 months ago and obviously did the doctors asked for some blood tests. I do have a excellent medical aid who paid most of the accounts and those outstanding I settled immediately myself as I NEVER received a call from anyone stating that I have an outstanding account in my life! Since I was discharged I received SMS and call from all over South Africa about Mr or Mrs A to Z account that is outstanding and I will be handed over!! I phoned Ampath Centurion several times speaking to a "Alicia" and "Graatjie" of which the last person managed to find 10 accounts with my contact details on and rectified it. This however still continue weekly with call from Cape town, Port Shepstone, Durban and Centurion to name a few.

This is going to give me another "stroke" as this continues at any time of day with account that does not belong to me!!! I also have responsibilities, management meetings and get interrupted in my work life as well as private by this company and despite all my calls to their head office it still continue!!!