neuropsych assessment re tamoxifen

Help. I am experiencing terrible memory and cognitive effects from tamoxifen. My insurance company have made me do 3 neuropsychological tests. The last one basically says nothing wrong with my memory. Ha! Come live with me for a week! I wonder if anyone has had something like this where you have to prove you are not right even though the test says you are fine. Its a hideous situation as I am like Dory from Finding Nemo! I have been advised to challenge the test because theyve had what is simply just a good result during the test. They are aware of the research on memory and tamixifen but im stuck with this neuropsych assessment which does not match my symptoms. Help. Thank you.