[Rambunctious]

This happens at Coles without specials.
Bought some oranges at about $3 and was charged for cherries at $15
Also watch out for the scam some checkouts use (not Coles) in smaller outlets where they ask if you want cash out, and you decline, but get to check the docket and fine $20 cash out.
Every time I shop I check the docket within 4 feet (120 centimetres for the young ones) of the checkout before leaving because only too often I get charged for more expensive items i.e apples at $5/kg instead of $3.5/kg.

As for speaking nicely to retail workers, when I get fuel and they ask which pump number, I always ask which is the cheapest, usually gives them a laugh.