Unhappy Customer

I bought a cellphone at Cash Crusaders Hartebee****rt o the 15th January 2025 and within a couple of hours of using the phone the screen started going blank after a couple of hours it would turn back on, this kept on recurring. On the 16th January 2025 I returned the product to the shop and asked for my full refund as it was even clear on their policy that I am entitled to my full refund I was told that I cannot be refunded.