Person A takes a trolley from Person B outside a shop.
Person A gives Person B £1 for the trolley, then Person B says it was tricky to get the trolley unhooked from the other trollies when they got it.
Person A finishes shopping and the coin won’t come out out of the trolley, because the pin won’t go in properly.
Shop assistant at the door says the trolley has been broken for ages.
Manager refuses to refund Person A the £1 as “when they are busy they get all the broken trollies out” and “people are told to return the broken trolley to them(?)”, although Person A knew nothing of this and Person B didn’t return the trolley either. His stance is that Person B robbed Person A so it's not up to them to refund the money.
Who’s at fault here? 