My brother got that same brand last Christmas. The instructions had missing steps and the pre-drilled holes were off. Took two of us three hours with a cordless drill.
My cousin bought a bookshelf from them last year. The box said assembly time was 45 minutes. We spent twenty minutes just trying to match the weird diagram to the actual pieces. Had to re-drill half the holes because nothing lined up. I still get annoyed thinking about that afternoon.