I've got something similar: two charges for the exact same amount on the same day. Both with Dine In Victoria. I KNOW I didn't eat the same meal twice on the same day. This results in more than just a $2 difference... but it is hard to set aside the time in a busy life to chase these things down.

And I have another case the other way, a food receipt that never made it to my Visa bill. So far I'm ahead, but if I complain that I got overcharged, shouldn't I mention that I'm missing a charge?