Worst shopping experience of my life

I signed a 2-year contract for a tablet with 5 gig a month at the Loch Logan Waterfront in Bloemfontein. Delivery was promised within 6 days, 3 weeks later I'm still waiting. I twice spoke to the salesman involved who promised to phone me back and never did. For the past 8 days I've tried on 9 occasions to either speak to him or the manager, neither answers the phone. I contacted their customer care to cancel the order so I can try another service provider, their reply is to contact the store. I have no idea how. We live 400 kms from the nearest Vodacom shop and cannot travel that far again just to cancel an order or to get answers from them.