I know my Discover card sometimes gives me 5% off from online purchases during a certain quarter or bigger discounts on particular things from Amazon if I go th

I know my Discover card sometimes gives me 5% off from online purchases during a certain quarter or bigger discounts on particular things from Amazon if I go through their "Discover store". Maybe they have a bunch of these types of credit cards? I'm not sure how returns would work in that situation though, I guess you have to return it through Zinc.