Cheated of my win a car entries

On Saturday 01/12/2018 I decided to shop at Checkers Westgate mall. I paid using my card and was given my till slip and receipt of EFT. The cashier then decided to keep the competition slip as I had qualified for 12 entries. I called Checkers on 04/12/2018 to ask for my till slip number as I needed to make use of the number to enter the competition. I was told I'd be given a call as they would reprint the till slip with the till number and it's been more than 24 hours now and I still haven't heard anything from them. Could whoever is going to deal with my case please make contact with me once they have my till slip number. Details of the receipt are as follows. Total value of goods is R404.20 C0108 #0020 10:32:13 011218 S002557