Re: I was banned when my account was hacked but EA wont let me open a case
You first need to recover the hacked account, make sure you have as much info about the account on hand in order to verify ownership.
If you believe you have been hacked take appropriate measures to secure your account and associated E-mail account https://help.ea.com/en-gb/help/account/secure-hacked-ea-account/
After you have recovered and secured your account and associated e-mail I would suggest changing passwords and enacting 2 factor ID.
Next you will more than likely have to dispute the ban, make sure you provide them with the info about the hacked account and the recovery of the account.
If you believe that a sanction (Suspension/Ban) placed on your account was by mistake you should reach out to the Terms of Service team https://help.ea.com/za/help/account/information-about-locked-or-banned-or-suspended-accounts/
Best of Luck.