My nephew (without my permission) saw something on reddit and changed a launch option in the game that unlocked a legendary skin and got loot boxes on my account. I am not a member of Twitch prime and have tried contacting respawn but it doesn't allow an email option, only talking to a live rep that keeps timing out. I am trying to speak out so they are aware I am not trying to get free loot and end up with a ban.
Is it simply a case that your nephew linked a Twitch Prime account to your EA account @Hydromorpher. Doing so will grant you some cool in-game content.
If you have Amazon Prime then Twitch Prime is a free bonus.
Neither him nor I have Twitch Prime or Amazon Prime. He added a launch command that has made the game think I have it and got the legendary Pathfinder skin and 5 loot boxes.