Trying to process what you mean, I've never encountered that bug before. It may be only in the demo version. If you can give me more details about what you did leading up to obtaining 400 packs I can solve the issue. The only way you should be obtaining that many packs is by winning at least 100 times in Hard difficulty.
Viewing post in STRIP Battle Action Cards [Demo] comments
Most frequently, I'd win a pack or two from beating Arc, then open packs as quickly as possible. Usually there's the pack I won, then a basic pack, then an energy pack, and it keeps reopening packs. Sometimes I insert a code to win more packs before doing so, which also causes there to be a *load* of packs. I'm going to play again tonight, so if I run into it again, I'll take better notes.