you added the study history period by period right?. i mean like 2012-2013 aa college. 2013 - 2014 b university etc. maybe try deleted the one that's wrong and add a new one.
It's probably too late, but what I guess is you need to delete that entry of study and add a new one.
I did a stupid way. I withdrawn whole application and send a new one cuz I didn't know I can just update file.
At least got that 15 points back