Found another bug but it's a little harder to explain:
So, I went 3-0 (twice against nmel and once against quiller) and then I went to play James. At this point, I'd bought the pieces that I thought it took to make the perfect deck and I'd upgraded my HP once.
When I click James and said I wanted to challenge him, there were two links:
Opponents Turn and Pick Deck (or the like)
I thought that was weird, but I click Pick Deck. I decided to go with my current deck, so I clicked Current Deck, but now it contained 75 pieces and it wasn't just all of my pieces multiplied by 3, either. In the deck, I should have had 2 charismatic generals but I had 4. Anyway, now I had 75 pieces in the deck and the page had no links on it too.
I went back two pages and just chose 'opponent's turn'. I figured this might be a work around. It let me start the game and James made two moves and then it brought me to my hand... which only contained 9 pieces. I knew this was a bug at this point, so I went back and just decided to make a new deck altogether. Only, now my collection consisted of 119 pieces (I'd bought 5 at most at this point).
Weird bug.