Toyota has been having a breakthrough in battery tech since 2011. That breakthrough was then a few years away.
Fastword over 10yrs later and Toyota is at the cusp just years away. There road map has it listed as releasing in 2028 (originally was 2016; but who’s tracking). Almost there guys. So close you can practically taste the rare earth metals.
/s
My advice speak with a lemon law attorney. First hour consultation is free. They won’t take your case as it’s a used car but may give you advice.
Right now your only recourse is to keep taking it in until they tell you to kick sand or you run out of warranty.