I have bought several thou of the winny primers this year and they have been really good about sending refund checks as long as you follow the directions.
Mail in rebates, cheap trick sale. They get your money (sometimes a long time) and USE it, entice you to buy more. Usually on overstock or excess product so they cut their inventory loss. Sometimes on discontinued product. It is a slight savings for consumer, usually just covers taxes. Like store coupons, most don't get used.
Once worked commissioned sales for a major nation-wide corporation, selling deliverable stuff that had a $75 mail-in rebatable delivery fee, on merchandise above a certain price point. The stated rebate refund time was up to eight weeks, but longer became the norm, and angry customers also became the norm. It didn't take long for it's main nation-wide competitor to seize the moment and offer non-rebatable free delivery.