Dischem refuse to give my money backfor an empty Polaroid box

I went to a dischem on the 26/05/20. I bought a few things including Polaroid wireless earbuds, read at the back of the box for specifications, then proceeded to pay R300 for that and left, when I get home, I found the box was not sealed and the earbuds were not in the box. I went back to the store the following day and I'm told that the cameras show that the box was sealed and they won't give me a refund. The store manager promised to get head office involved but still came back with the same thing to prove that nothing was done, he decided that he won't give me my money back. I paid R300 for an empty box and their cameras say that the box was sealed, how did they see the tiny seal on the camera??