Mcdonalds
Told i had won a prize then denied it

I was one of the winners of the R5000 takealot gift card in the mzanzi millions competition.
This was from one of the chance cards where you sms your code on the sticker to the number provided and then it is a lucky draw.
I received a call last week saying I had won the gift card although in order to claim it I still needed the sticker with the code on it.
Nowhere on the sticker or on the game boards terms and conditions does it state though that you have to keep the sticker after smsing the code to the number provided in order to claim your prize and then when you no longer have it even after the competition is long over they will not give you the prize which you have won.