Cashier did not give me my 100M receipt.

I Bought some few groceries including R29 MTN data 100M bytes, the cashier only gave me the receipt for the groceries and all the groceries except for the 100M bytes receipt. When I got home which was an hour later, I only realised that she did not give me the data that I paid for. I went back to the shop (Checkers SP Pavillion , Oakdene) but she had knocked off already, I requested for the Store Manager who enquired and called the cashier who was assisting me on her cellphone and she said she gave my data receipt to one of the colleagues from the cash office to keep it in case I come back. When the Store Manager requested my receipt from the cash office, no one knew where the data receipt was. Store Manager had to request another cashier to reprint my 100M data receipt. Management did not reimburse me with petrol of coming back when it was their fault.