Beans may be a poor example, but at the time of going into the shop said beans are price X for everybody. What they cost 2/3 years ago does not matter. My arguement still is why shoud a new customer get the beans cheaper. Surely as said there should be a set price.
I know I am not going to win this arguement, but loyalty counts for nothing. I will be looking around to see what price the beans are in Tesco's