Private document addressed to the wrong person.

I went for blood tests at my gp in April, he sent it off to Ampath Pathologists. Yesterday my father brings me a letter from Ampath which was addressed to him and of course he opened it. This is a PRIVATE AND CONFIDENTIAL document that was addressed to the wrong person. I have not been on my fathers medical aid for 10 years and i changed to my current medical aid 4 years ago which is not even the same medical aid company to his, so my fathers details are not mentioned anywhere. Ampath managed to not only address this PRIVATE AND CONFIDENTIAL document to the wrong person but when i spoke to the senior manager, she informed me they also have information like his ID nr linked to my account. This is an UNACCEPTABLE mistake. I will be taking this further and i will be getting my attorneys involved. Be careful public, not even your medical information remains private to you.