Grade 8 placement

My son is doing grade 7 and I have app**** online like other people to my surprise he was offered space to some school that I did not apply for nor know the location . I have tried to email them but still my application is not responded to. And I have a daughter in Hoerskool Gert Maritz and I indicated to them that I would love them to be in the same school but they still refusing to place hi