Mothers Day Madness!

During the Mothers Day Special discount period (2nd week of May 2023) I purchased a winter poncho - from me to me - the item now has quality issues and I am told that to exchange it for a new one I will need to pay in the difference between the Rand price that I paid at the time (discounted price) and the normal price now !! Surely if the item has a quality issue I should be allowed to swop the item for a new one! Definitely not the response that I was anticipating.