Sales Person not trained on product availability

Abit annoyed with Telkom mobile. I app**** online for a contract after visiting many branches only to be told there is no stock of the device I wanted. Anyway, I called the number for online sales, they have vetted and approved me immediately. Told me to wait 3-5 working days for delivery. 2 weeks later still waiting??? Suddenly, there is no stock of the device in my preferred color. I need this contract cancelled. The device should of been reserved upon approval. I am trying to get a hold of the correct department to cancel this deal...no luck! Upsetting to know that I have 4 mobile contracts and 2 landline contracts with a company that is proving to be inefficient. :( Please can someone get back to me so that I can have this deal cancelled before I am billed unnecessary.