Unhappy customer

Bought something from Cotton On @ Carnival Mall for 299 around July went back around that time to try and exchange the item but had lost my receipt,I was then told I can’t get the money back I have to take something else since I don’t have a receipt I asked if they can’t put the refund on their store voucher I was told they can’t do that as well because of the receipt.So from then I have been trying to find something I like in order for me to do the exchange without any luck so today I decided let me rather exchange with an item from the baby session @ their East rand Mall branch when I got to the till I was told the item was on sale so I have to make the exchange with the sale price which is 149