http://www.tesco.ie/csr/index.html#2
After this thread on boards, I went in search of this policy and sure enough its on Tesco’s website, its worth keeping this in mind next time you goto tesco’s 
No Quibble Policy
Our “No Quibble Policy” is our way of showing customers that we always charge the right prices in our stores. It states that: “in the unlikely event of you being charged a price at the checkouts that is higher that the price mounted on the display, we will give you that item absolutely free and without quibble”
