We are contacting you regarding a past Prime Video purchase(s). The below content is no longer playable on Prime Video.
In an effort to compensate you for the inconvenience, we have applied a £5.99 Amazon Gift Card to your account. The Gift Card amount is equal to the amount you paid for the Prime Video purchase(s). To apologize for the inconvenience, we've also added an Amazon Gift Certificate of £5 to your account. Your Gift Card balance will be automatically applied to your next eligible order. You can view your balance and usage history in Your Account here:
The only thing that surprises me is that anyone is surprised by this. If you buy a physical book from anywhere, you own it. If you "buy" the rigth to play a movie (or read a book) from amazon, you own nothing. Usually they don't show that so clearly but that's the reality.
Hell, this isn't the first time Amazon has done this, even if it's the first time they've done it for video. Of all things, they retroactively removed a version of 1984 from Kindle, including having Kindle devices delete local copies the next time they connected to Amazon.
If I recall correctly there was a time, where they did a deal with Disney a few years back. Disney wanted to bring one or more of their classic animations back to the cinema and Amazon disabled playback of those movie(s) for that time even for people who had "bought" them.