How Low Can Esso Go?

Thieving little b#@*!^ds. As if petrol wasn't expensive enough. Yesterday the petrol light came on and as I've done a fair bit of running around since then, I thought it best I pop a bit in the old tank. Asda has the best deal price-wise but also the longest queues so I resorted to an Esso station nearby. Very carefully I put in exactly £10 - EXACTLY £10, yet by the time I'd got to the kiosk to pay it'd clicked another penny. Complaints fell on deaf ears. It's only a penny. I know it's only a penny today, but if it's a penny every time I go there, a penny for every customer they have, that's a lot of pennies extra they're clicking.

original image: wikimedia