Terrible service shell garage Protea South

I bought chocolates that were on special on the 06th April 2025 at Shell garage Protea South ,although the items were on different sizes i then requested to exchange the items of the same size to avoid paying a lot of money. The sales person refused to give me cash back and i was forced to take the items i did not intend to buy. He informed that it the policy of the garage that they do not offer cash back.