That "case number" you got is useless. The new interface is intentional. It is similar to the crappy one on Xbox. The one on my Roku XD still uses a "good" interface, but I never watch Amazon on that device (I don't watch on Xbox either, but mostly because it would force me to manually change the sound from 5.1 PCM to Dolby).
The limited FF/RW I can live with. It's the clunky pause/stop/back to menu/choosing TV episodes that irks me.
Charter Spectrum 60; d-link dual band router
Roku 4210, 3710; Xbox One, 360; Samsung BD player
Samsung tablet; Windows Vista laptop; LG phone
Toshiba DVD-R; Sony AVR; Panasonic AR
1080p and 720p TVs