What an inconvenience by Vereeniging Mc Donald's

My kids went to buy Big Mac only to be ****** by your cashier with change and claimed my kids were lying but the store can't prove that kids are lying. I asked them to check cameras because they were adamant that the cashier was right, they told us we must wait because the person who has access to cameras is off duty (whose business is that) ....how do we even wait when we need that money for traveling on that very day