Complaint to Global Hardware

Hi there, I am experiencing a very bad customer service with Global hardware in Ottery Cape Town. I bought a bulk of items from their store and they only delivered the stones and sand, there is still a lot of items they need to deliver, however, I am being told i cannot be helped since I lost my invoice. I have sincerely asked that they check from their side as I am not willing to lose R13 820.00 over something that can be resolved.