Thievery at kfc vangate

My order number was 297 and ordered this today at vangate mall spur. When I got my food one of your staff requested my slip after she tore it in half which is the norman process. What I found strange was that she wanted to keep the torn slip, I left kfc and stood by the window watching this lady who in turn gave the slip to her friend, who then used my slip to enter some competition which is printed on the back of the slip. Why was this not left for me? Why is your staff giving my slips to their buddies who enter the store. Please sort this **** out and who ever goes and buys by kfc vangate please don't let them keep your slip cause the last few digits of your card number are on those slips as well