Visa Reward Card Redemption Questions

On the Spin and Win I got a "50 SB Rebate on your next Visa Reward Card Redemption", but I am new to this. It seems to mean I have to buy a Visa Gift Card and redeem it within the next two weeks. Is that correct? Can I use them anywhere, like my local grocery store? Or does it have to be online, and if so, how does that work, given that the amount on the card won't be the same as the amount of purchase?

Thanks!