i almost never get the 3rd slip with unique code even when my receipt says i have entries?

Maybe it's my fault for not being vigilant enough when paying at the til... But it seems like the cashiers are using busy/peak times when everyone is not really paying attention to detail. I have at least 6 slips, all written "you qualify for 2 entries into the competition" but alas - no 3rd slip with the *120* unique code. I even found one with 6 entries, but no unique code slip. I never throw my receipts away, so if i dont have it, i didnt get one! I feel very cheated because it seems like either Checkers is robbing us by deliberately not printing the 3rd slip, or the cashiers are being ******* themselves and keeping that last slip for themselves? Can we get some responses please? I see i'm not the only one this has happened to....