Surname Amendment

I app**** to change my surname at the dept of Home Affairs in Orlando, Soweto. I sent all the paperwork required to change my surname and use my father's surname. Documents that were required since my Mother and Father are no more, I submitted an Affidavit written by my uncle(father's brother) and mine to approve that we agree to change my surname, two death certificates for both my parents and filled the forms. I paid as well, I was told this would take 6 months and I patiently waited, now when I call I am told that I need to submit DNA Tests after all the documentation and affidavits submitted. Now my things are on halt for something that does not make sense and this was not even mentioned on list of things required to change the surname. Please explain how as this does not make any sense because I provided all the necessary documents.