Hmm, fascinating. I took advantage of the exact same thing on "Mama Celeste" frozen pizza at "Stop & Shop" here in the US a few years ago. But the free pizza

Hmm, fascinating. I took advantage of the exact same thing on "Mama Celeste" frozen pizza at "Stop & Shop" here in the US a few years ago. But the free pizza vouchers were printed on the sales receipt, rather than on the product. So I could return the single purchased product and end up getting all the pizzas completely free. I emptied their pizza freezer. The store figured out what I as doing pretty quickly, but didn't much care as they were reimbursed by the manufacturer and thought it was pretty amusing.