VODACOM NOT HONOURING ADVERTISED FREE ITEMS

Took out a contract in December via Vodacom online which advertised the IPHONE and a free Beats Headset. Phone was delivered but no headset. I have sent repeated emails and phoned continuously to be either told that they are out of stock (yet I confirmed at the time of taking out the contract that stock was available). Very strange that you continue to advertise this special despite not having any stock? After several emails I ended up receiving a phone call saying that stock had been received and would be delivered within 1 week. This has once again not happened. December - February and order still not fully completed is unacceptable. Is this advertising of a free headset merely a marketing ploy. So customers just done receive these? This would seem to be *********. Surely a customer has been extremely patient by waiting almost 3 months for the promised headset. please can I get some feedback on this long outstanding order which is unacceptable.