What now telkom.

I am very disappointed with the service. On the 29th of November I signed a new contract with a device that they didn't have in stock, but the sales lady guaranteed to me she would phone me during the week to pick it up, latest Thursday (3 December). Nearly 3 weeks have gone past, and my new invoice has been made where they going to charge me for my service without having the devices as per the promotion signed. What am i supposed to do? I have got emails between the saleslady and myself, always indicating it is next week, the "next week" never arrives and next week it is Christmas, which i should be handing out the devices as a gift!!!