Unfortunately, you have been taught and are executing Agile in the completely wrong fashion. My first guess would be, you are actually working in Waterfall, but your managers have labeled it Agile and cherry-picked the parts they liked.
Agile has a remarkable resemblance to both communism and faith healing: Every time I say it doesn't work, a true believer replies and says I wasn't doing it right or I didn't believe in it enough.
