Poor service and delivery of products

I ordered 2 x pairs of crocs 3 weeks ago, it took 1 week to get a confirmation out of them and another few days after that to get tracking information. Parcel eventually arrives but one pair is not there.... But delivery note on the box states 2 items in the box..... I phone the call center to ask what's happened, to be told that there is no stock.... But there is one in the warehouse that they can maybe send me, they will phone me back in 10min. It's over 2rhrs later and still no call from them! I have emailed I have phoned..... Nothing. I am totally dissatisfied with the level of service. We are expected to make payment straight away when ordering but they can take as long as they wish for everything. Totally ridiculous