Ok I just read the OP again. So you told her you would be back for the earrings and to *maybe* the bracelet. And then I assume because your kids were mucking around you were longer than the stated 10 minutes? She had every right to put the bracelet back on display!
I assume then at some point she has realised that the prices were wrong and swapped them. Which she also has every right to do. She then gave you the wrong bracelet, either by mistake or on purpose.
Either way, you paid the correct amount for that particular bracelet when you were hoping to pay a far far cheaper price for something worth much more. You then went back to the shop and argued with them for 2.5 hours about getting the more expensive item for a much cheaper price :-/