Covid positive but got proof i am negative

On the 10th of December i went for a covid test at Pathcare. Result came out as negative. 14th of december a lady called Andrea called me from the department of health western cape telling me i am covid positive. She didnt tell me where she get this information and i pushed her for a answer. I am very worried that the number of south africa's covid cases are very wrong. How can you call someone telling him he is positive and think nothing will happen if this information is wrong. Should i go in isolation? Must ny family go away? Must i take leave?

I lost my trust in government and will like to take this further