Go there https://help.ea.com/fr/contact-us/ and tell us what happened to you.
I would suggest to add this details so it will be quicker to solve your problem:
Mark and model of the device
Platform and OS details of the device
Country, State and City they played the game in
Version Number of the game
Game Mode Affected/ Challenge Name:
Which league they were in.
What position within that league they finished.
Date of Incident:
I did that today because I did not get my reward last week, and they just provided me my missing reward.
Don't worry, you'll will get your reward at some point !