Cashier Crime Mr Price

I went to buy a denim jean at Mr Price Bedfordview and the cashier scanned the jean and another pair of pants without me noticing. I tapped my card, trusting that I am only paying for the one item. When I got home I saw on the receipt there were two items. Went back to Mr Price to my surprise the manager told me they can't assist as the cashier is not there, they don't have cameras to verify and that there's nothing they can do. They couldn't even give me an email address for where I can escalate this crime that was committed.