Family Tree DNA Their testing did not match up with proven genealogy. I am a registered Cherokee (3/4% by blood) they say I am less tan 1% Houston Texas

I have proven (to my satisfaction) their testing and research methods are slipshod at best.  I am a Native Cherokee and am ¾, by blood, Cherokee.  I was born and raised on the Cherokee Nation in Oklahoma.  My mother is 100% Cherokee and my father is  1/2 Cherokee.  Both sides of my family have been on the Dawes rolls of the Cherokee Nation since the early 1900s.  We have traced my maternal family back to the early 1600s.  We have traced my father's mother's Cherokee roots to the middle 1700s.  Family Tree tells me I am less than .1% Native American.  I called Family Tree and they told me the magine of error was +/- 10%.  That doesn't even put them in the ball park.  Their DNA testing appears to be slipshod at best.