i think i remember BR saying that it was intentional that you not be able to logout and have stats stop tracking - it would be too easy to cheese massive ratios by quickly logging out every time you put yourself in a bad position.
this might not apply to you (or anyone) but in case there's someone who has the same problem i had:
my advice to just play and do your best not to worry about your stats. i spent a while thinking too much about them and got frustrated every time i didn't hit a 15 ratio... it's just not realistic to expect to beat your average every time you play, especially if you aren't new. if you get frustrated with stats you don't consider up to your standard, try disabling them for a while and rediscover playing for the game instead of the numbers