Poor service

Today I went to jet store Mokopane The Crossing to purchase a trouser, so when arrives home I found it small then I returned it back to the store for an exchange, to my arrival they told me they can't exchange it without having the bank card I purchased with, o returned and went to get the card, after they swiped again so when I wanted to know why do I have to pay again the cashier referred me to the manager,so the manager was rude and even saying that there work with huge transaction I'll get my refund after 24 hours... When I asked why they didn't notify their customers about their new law she shouted I ended up leaving the store with the frustration