Vodacom Expect More Promotions

I Upgraded my Vodacom Contract to A premium + Package. If I took a certain package with a certain phone I was told I would receive a voucher to the Value of R5000 to use anywhere because Vodacom is running a promotion until 6 December. I received the sms today. I phoned in the voucher is for Kulula, I am thankful for the voucher but the problem is, I can't use it because they don't have flights to bloem and took the spesific phone because of voucher. I contacted vodacom and the lady told my she knows nothing of this deal. I went online and saw there are various deals online for this promotion. I see Vodacom states that vouchers can't be exchanged for other vouchers and the list goes on. I feel Misled and want to cancel my upgrade.