Same as above posters. Coin balance keeps randomly changing between sessions and sometime no showing updated totals following a match. Challenges and rank completion is also showing incorrectly and varyingly - challenges I know I have completed are appearing again.
It looks lie the various servers (game, lobby, stats) are not syncing up correctly and each session is showing something different. Depending on which server you hit you seem to get different coins and challenges showing.
There is a reddit on this as well:
https://www.reddit.com/r/PvZGardenWarfare/comments/36zdtf/help_coins_are_stuck_at_3k_and_wont_go_up_cant/