Cannot upgrade contract

I am very disappointed with Vodacom's service. Been eligible for an upgrade for the last month, but cannot upgrade due to the fact that the device i want is out of stock. All they can tell me is be patient and wait until next week. Today i called again and the lady advised me that the supplier (Asus) is experiencing delays. I asked about another device that i was also considering(Acer), but funny enough they are experiencing the same delays. I am now considering cancelling my contract and taking by business to a different provider. Anyone but Vodacom. Really fed up now