I have Prime, Netflix, and HBO and still run into this regularly. It's really annoying. As soon as GOT is done, I'll likely cancel HBO - it doesn't add much value. Netflix is hanging on, barely - every time I go to cancel, I find something interesting to watch, and that keeps me for another month or two. But, it feels user-hostile and with the price going up again, I'm that much more likely to just cancel and be done with them. And I hate the idea of relying on Amazon even more than I already do.
Le Sigh