Price hike after placing order

Price hike after ordering from Spar. The pre authorised amount was R101 and the amount charged after delivery was R177, with one item out of stock. I asked why they charged this much, they just said that is the amount the product cost and that I won’t be getting it for R101 (promo) The support team are useless. Spar will not see my money as the amount is authorised by them upon sending the package. This is Spar Somerset West that does ***** on orders. They show a promotion, you check out with the promotion, but once it’s delivered, they charge you normal price.