Re: Arena grand prize bug
@cqeldnr3 Now the not so bad news.
Since evident from your screenshoot does suggest you should have the plant unlocked as a reward for your efforts, I would suggest you click the HELP CENTER link at the bottom of this page and open a 'missing content' case with EA.
You will need to provide a screenshoot of your player ID along with the images you have posted here, hopefully the advisor can help to unlock the plant on your account.
Good luck.