I had an issue once when the cashier/owner was meant to give me 1p change from a tenner literally I spent £9.99 said she couldn't give me change as she had no copper I.... I was like you are a shop owner you don't get to just round up because you don't have any change I had literally seen the person on front of me pay with change. So I held firm and said either give me 5p or the next smallest coin you have otherwise I'm calling the police as you have actually just stolen from me.i was about 15 at the time so going back some 23 years, I refused to budge out the door way unti i got my money... they called police on me when they turned up officer at first had an attitude with me until i explained the situation owner then got into trouble for stealing from a child and she gave me my penny. A few weeks later she tried the same with one of my friends. Again police were called his (my friends mother) wwnt round after and smashed this owners face in. Owner never stoke from a child again as far as I'm aware.