Zara Claims I Used My Birthday Gift Card but It Gave Activation Errors Every Time

I wanted to use the gift card gifted to me by my friends on my birthday several times, but every time it gave an activation code error. I tried to use it in the Oysho store last time, I couldn't use it because the activation code didn't come to my phone there. So when I contacted Zara customer service today, they told me that the card was used on 26.09.2024. It is not possible for me to use a card that gave an error anyway, so when I asked which store and which product was bought, they did not give me this information, they just said that it was used in the store on 26.09.2024 and passed it. I didn't use that card and I want to know where my balance in it disappeared.