Missing items from the parcel/order.

I made an online purchase on Sunday and I received my parcel yesterday (Tuesday) but to my surprise not all items were packed and I didn't receive any communication concerning other items. I immediately went to Middestad Clicks where I collected the parcel but apparently online customer service was closed already. I left my details and packaging list, then today (Wednesday) I got a call that I must wait for 48 hours because they will investigate the order. I logged a query and got an email that I must wait for 72 hours. This is too much as I've run out of the items I ordered, on the other side am not sure if I can use the ones I've received already.