Competition Error (Unfortunately, this till slip has already been used)

Have literally just opened my 850g Parmalat Cheddar Cheese (from Spar 16th Nov) and noticed a QR competition code. Scanned it to joined Parmalat whatsapp, went thro the process, scanned the Spar receipt, only to be advised that "Thank you for your entry. Unfortunately, this till slip has already been used. Please try again with a new till slip. Ts & Cs Apply." Re-scanned it and the same reply! So either Parmalat have a system problem (probably), or somebody at Spar Century View (unlikely) are printing off duplicate receipts and entering the competition. Either-way, it does not fair well Will Hellopeter the same message for Parmalat