Guaranteed gifts but only while stocks last

Took out a new vodacom contract 2 weeks ago, they advertise everywhere about the guaranteed free gifts with any upgrade or new contract. I was told out right that it is only while stocks last and that there wasn't anymore gifts. Yet everyday I see that same advert on TV promising a guaranteed gift and the whole vodacom shop is full of posters promising a guaranteed free gift. Vodacom should really look up the word guaranteed in the dictionary.They are misleading us with false advertising.