Sephora Refused to Exchange Unused Benefit Brow Setter

On May 3, my aunt purchased a Benefit Brow Setter from Sephora Ataköy Plus as a birthday gift for me, which I received on May 12. Since it wasn’t something I wanted, I went to Sephora at Capacity Mall to exchange it. However, they claimed the product had already been opened and refused the exchange. My aunt specifically selected it from a sealed shelf, and I never even opened the package myself.

How can this be explained? Why am I left with a gift I cannot use, despite having done nothing wrong? Sephora must address this issue, as no one can prove I opened the product. I expect my concern to be resolved fairly and an exchange to be allowed.