Couldn't you not screw into the mortar line instead of the bricks. The only problem is with no more nails is it would take longer to clean off and could do a lot more damage than just four or six screw hole.
I'm not to sure if these are right but here you go.
http://www.ebay.co.uk/itm/TP-22-Meissel-fur-Hilti-TP-800-TE-804-Spatmeissel-/330569879479?pt=Elektrowerkzeug_Zubeh%C3%B6r&hash=item4cf7800fb7...
It might be worth giving the manufacture a call and ask for the fixing kit that would of come with the fridge when it was new.
http://www.espares.co.uk/part/fridges-and-freezers/aeg/p/1084/143/0/0/539712/integrated-fixing-bracket.html