Made a fool for a price I won

Wow I'm not happy with OBC I won their Facebook spot a golden egg competition and i got a message too go and collect my prize which was R2000 voucher when I arrive at the store I get told they don't know anything about this competition..and I inboxed the page and they told me they will alert the store went again still not alert from the shop why are you playing with us like this it's beacuse were poor this is wrong I loved OBC but now nope