(1)At supermarkets, particularly for fruit: red plums and black plums cost the same/lb, xxx apples and yyy apples cost the same/lb etc. each have their unique bar and product code on them, but sometimes they get co-mingled. You get to the cashier who weighs them, but somehow she enters the red plum code wrong [in one instance they had to call a fruit person]--if I had, say, one red plum and one black plum, weighing them as ONE item, it would still cost the same, yet they are spending lots of time trying get it EXACTLY right.
(2)I was in a McDonalds and ordered a soft-serve cone, but they ran out of cones, I suggested they put the same amount in a CUP--at that particular MD it was too difficult an operation to deal with [I actually prefer it in a cup!]--they couldn't sell it to me.