Vaal Mall Truworths - Simon and Riette

I purchased a pair of pajamas as a gift for my mother using my credit card. Since I live far from her, I gave her the receipt in case it didn't fit and she needed to exchange it.

She visited the Vaal Mall branch to change them, she didn't want a refund, she simply wanted a gift card as she couldn't get what she was looking for. They refused as she did not have the credit card that made the original purchase. The tags were still attached and she had the original receipt, I don't understand why they would not allow her to exchange or credit? Simon, the store manager was most unhelpful and Riette, the area manager was even more unhelpful.

I am not able to return with my credit card as I live too far.

Why can she not be credited with a Truworths gift card?