Still waiting for order (3 weeks)

I have been waiting 3 weeks for my online order. I even decided to collect the goods at the store (Strubens Valley). I phoned the store, they just say they don't have stock. I phoned the national call centre, they don't have stock.

I don't understand. How can you sell me a product, I pay for it, but you don't have stock.

This is unacceptable!!!!