Game Bethlehem won't see me again

Good day, so in December 2017, we bought a tablet from the game store in Bethlehem Free State, it started giving me some problems so we've send it in it's still under warranty/guarantee so I got it back on May 30 2018, and then last night it started to restart everytime, my husband took it back, and they simply refuse to replace it for me... They will send it in again...

I've called game instore manager and I was not happy with how he managed the situation, they have told me when I bought it that if anything goes wrong while it is still under warranty/ gaurantee they will replace it for me...