16 Weekend Leagues and always stuck at 7 wins

Hey cupcakekps16​ sorry to see that you are frustrated.

From reading your post, honestly, if it feels like it's a case where you are running into an issue with the game difficulty and perhaps hitting the same point each week, not skill-wise but rather patience and attention. 

It happens to everyone from time to time, I had a number of weekends where I ended up with 8 wins each time and found that part of it was that playing a number of games in a row meant I wasn't paying as much attention as it went on.

It's something to keep in mind and one of those things that we often forget. It may not be the cause of the issue you are seeing, but was for me. By taking some time to relax, I found myself coming back refreshed and  it turned into a number of extra wins on average each week. 

You raise some interesting theories in your post but a lot of the things are simply not part of the game. There is no hidden balancing in the game; there's no bug that would cause this, nor would an account-related issue.

Matchmaking, yeah, that can play a part, but the game doesn't give anyone an advantage and simply tries to match you with the best opponent they can for your level.

Let me know how you get on.

Darko