unfulfilled promise of ring resizing at American Swiss the Glen Mall

on January 2021 we did lay bye rings that where on special at the American swiss at the Glen mall, my ring was big and the agent assured me that the resizing will be for free once we complete payment for the lay bye. To our surprise, on Tuesday the 1st of June 2021, upon completing payment on the lay bye, we where told that the cost will be for R460 not free as we were told initially. I need help ASAP as this is not fair.