Demand for payment of someone else account

Very Rude and Poor Service. I have been handed over for a ampath account which does not belong to me. I tried to explain to them that I had no blood test taken in years and their is a huge mistake. They confirmed that the patient the blood test was taken for is someone completely different to me yet they keep on demanding I pay it and say that I am the account holder and they have my ID number. How on earth could be responsible for someone else account. And they yell over me through the phone down in my ear, tell me I am wasting their time I should phone ampath. Ampath says they can not help me I must phone vericred and explain. Vericred dont have the ID number nor the date of birth of the patient which has a different name and surname to me that I am supposedly responsible for paying the account for. I get several calls a day, 3 to 4 demanding messages a day and they just refuse to stop even though I tried explaining to them its not me over and over again