Refund denied

Hi, I am not sure if you are the same as bridge city store but I will state my case anyway. On Thursday 24 December 2020, I sent my niece to the shops with my card because I couldn’t go myself, places are packed because of Christmas shopping and I have a baby. So I gave my niece my card, an unfortunate event happened whereby he started shopping from this shop without my consent, he bought a pair of vans shoes. Immediately when my phone reported I quickly rushed to get him and took to the store to afk for a refund but they refused to give a refund even when I tried to state my case, I called their boss and pleaded, and motivated why I needed a refund he still refused and blocked me. It is such an unfortunate even for a store that is at the mall environment and also for the fact that they sold to a miner and still insist that they can’t refund even when told the purchase was not authorized. I am very disappointed and planning on seeking legal advice