Bad service

We are here at Spar Cala Eastern Cape, we bought 4 Royco cook in sauce and it was wrongly priced at R16.49 when we get to the till is R39.99 and the supervisor went check the price with us as they thought we were lying, there were about 20 sauces wrongly priced then the supervisor decided to run away and sent Mark Pittaway who came to us as soon we explain to him, he was rude and tell us unfortunately we will get the sauce for R39.99. is this how a manager can be clueless and treat customer the way he treated us. What is he managing if his stuff can price/place things in a wrong shelves.