Bad service at Truworths Groove mall

I am not happy about the service that I got at Truworths in the Groove mall in Pretoria Lynnwood. Someone bought me a present which I ddnt like with an account and I went there to go and ask to do an exchange since I have the slip n the item bought is still in a sellable condition.when I got there I told the item that I wanted to exchange with and upon my arrival at T the tills I was told that I can not change I need the account card,and this other lady also came m not sure is it's the supervisor or manager but by the looks of things is on e of the management,she told me that I need a letter,the ID of the person who bought the gift and my ID in order for me to exchange,this is an exchange for God sake not a refund.and worse pard I had the slip with me n the item still had price intact but nooo their store rule says I need permission letter and ID for just and exchange and now it has past 30days because the person won't have time now.so I am stuck with something expensive that I D not want. So my question is if those rules are not on their invoice so how the hell are we supposed to know that we need IDs and letter for an exchange .