Don't know if there is a point in posting failed attempts but anyhow...
First game: March 26th
Played again: Sept 26th, 27th
Did not reset my level 50.
Did not participate in the beta.
Did not delete any save files.
Did not clear my cache.
Did not boost, got to lvl 50 "legit".
Played a few Instant Action and Team Instat Action. Both from the start and by joining mid game.