Aside from that, there are two things I'd like to add:
1) It often takes around 2 weeks for accountdisputes to reply, so you will need patience.
2) With G2A, just like many other CD key sellers, you can't be certain that the product key is legally obtained or authorized... and that might result in a whole bunch of potential issues, from not being able to play the game at all (as the key might've already been used; also, EA may disable keys if they suspect that they were initially obtained or distributed by unlawful means) to getting banned.
