American Swiss review: Customer sold a diamond earring promising an exchange within 30 days

Hi, I purchased a diamond ear ring worth 11500/- Rands as gift for my wife at American Swiss canal walk store, cape town on 22-Nov 2019. I enquired before payment and was informed before making the purchase that Iam allowed to return or exchange within 30 Days. On 23-Nov 2019 when I go to exchange the ear ring as my wife didn't like the design, the store manager says that she had already informed me that it cannot be exchanged and explains me the policy very clearly.
MY COMPLAINT is that the policy was not explained clearly by the sales staff before purchase as they wanted to make a sale. My experience is the worst at American Swiss as the policy was not explained clearly while making the payment, I wouldnt have purchased if the policy was explained clearly to me as I was buying a surprise gift for my wife and knowing the fact that if she doesn't like I could return or exchange . I feel Tricked and Cheated by the canal walk American Swiss store cape town . Disgraceful.