Exchange policy a ****

Today i bought an item at MRprice Fourways and went to exchange it at Mr Price northgate and was told they cant do it, because sales is not reflecting and the sales lafy Keabatse also said they cant tell each and every customer about this policy that you can only exchange the item the follwing day, its not written anywhere in their terms and conditions, i was told to buy and come for a refund tomorrow, what a wow, why cOuldnt exchange n do a refund tomorrow,