Every once in a while, Wizards of the Coast makes a big mistake in rolling out their Magic: The Gathering cards. While some are quite noticeable, such as the whole Wvyern card back incident, others arrive a little more on edge.
So, in 1994, WotC created the appropriately named "Redemption Program" to help fix huge errors as they occur. To date, Wizards has only had to pull that trigger six times. And every time it has happened has been unique.
The first big error happened in 1994 and helped start up the entire program because of it. Legends came out, but cards had been distributed with a huge flaw. You see, that rollout had uncommon cards be placed into two groups, but due to a filling error only one of those sets were included in booster packs. One set of uncommon cards now had an alarming frequency, while the other was seemingly nowhere to be found.
After finding this out, WotC wanted to do right.
This being pre-widespread Internet usage, however, they did it the only way they could: by putting an ad out in Duelist Magazine. There they offered a trade of any of the numerous uncommon cards from the first group for any of the ones not released widely, with a caveat of limiting it to 100 cards per person, with no two cards of the same type being sent in for redemption.
Only two years later another incident came up, this time in Japan. The Mirage card Flood Plain wasn't printed in Japanese. Instead, the printer did an extra Crystal Vein. Thinking on their feet, they did a similar trade-in program, only this time for every two Crystal Veins sent in, the mailer would get one Crystal Vein and one Flood Plain, plus a Nalanthi Dragon as an additional "I'm sorry." Almost the exact same thing happened in Spain three years later with the card Eye of Ramos triggered the third Redemption Program action in pretty much the exact same way as the aforementioned Flood Plain card.
Incident number four happened during the Tempest/Urza's era in the late 90s, with a number of cards being quickly banned for various reasons. Seeing entire decks being torn apart now, WotC once again stepped in. As there were eight banned rare cards (Earthcraft, Dream Halls, Mind over Matter, Recurring Nightmare, Fluctuator, Time Spiral, Tolarian Academy, Windfall, and Memory Jar) now being unusable for tournament play, the company more-or-less said that for each card sent in you'd get a booster pack from that set that the banned card was from.
The game of Magic then had a decent non-huge error run until Legions in 2003. By now, the Internet was starting to kick in more and more nationwide. So, when an elvish preconstructed deck accidently included the card Snarling Undurak (which isn't an elf at all), alleviating the issue was a bit easier. Online, WotC apologized and said that if you sent in the Undurak along with a receipt of buying the deck, you'd get two Taunting Elf cards in return.
The most recent time WotC had to pull a Redemption Program switch was back in 2006. Some Coldsnap preconstructed decks had switched up cards with those of another deck, with Brainstorm being swapped with Essence Flare in a "you got chocolate in my peanut butter" sort of situation. This, time, however, instead of sending in a card for a card like all of the previous times, you instead sent the affected cards in with a receipt and, in exchange, you got a coupon for a discount on the deck was restocked with the correct cards in their correct places.
Since the Coldsnap snafu, WotC hasn't invoked the Redemption program again. Mistakes that have come by have been fixed quicker. Whereas printing errors or deck errors went unnoticed for a longer time even 10 to 15 years ago, today Wizards can know exactly what's wrong very quickly. For example, the recent Spacegodzilla fiasco had the situation remedied almost as soon as players complained about the card in question, with WotC fixing it in time for later prints that year.
The program is still active as of 2021 though, so it's possible that a future card trade-in may happen again some time in the future. For whatever the reason, though, WotC hasn't pulled the trigger despite a few errors in which they could have such as with the Buy-A-Box promo for Theros Beyond Death in January of 2020 that should have included a foil Nyx-styled basic land but included a non-foil instead due to a production error (replacement lands were shipped after or around the prerelease to local game stores so the issue could be remedied at the store level).
As for whether or not the company will fire the program up once again, only time will tell.