My tradable player turned untradable

So I recently to upgrade my right back I had 1.7 billion in my bank I'm sure you know that right backs are quite pricey so I went all out and bought a $1 billion rightback ranked up 4 times and I checked 3 days later for the right bag to now, be completely untradable I feel scammed and just want my 1.5 billion back I spent money on the game in the past please fix the mistake that you made I don't want any one else to be scammed like me thank you my user ID is 969803074639175680 please I love the game but this isn't right

Thank you for your consideration