Price suddenly escalated then lowered

I placed an item in my cart, priced at R799, and it continued to show at this price during the checkout process, but at the final stage Kalahari escalated the amount charged to my card by R50, even though the checkout page still showed the price as R799. But this was not an actual price increase on the product because they then once again showed the R799 price on the product page. Their claim that this is somehow the supplier's fault doesn't wash since the price only went up briefly, then returned to the advertised price.