Yeah, it's really poor. EA-CS is useless and CG's communication is next to nothing. They continue to allow these coliseum bans without a proper examination......I really don't understand this company. I just really don't. I've been playing since the end of 2017, and if I get banned in coliseum for getting a higher score than I should; they have 48 hours re-open it or I'm gone for good. That's how low my morale is with the current game situation.
ANYWAY.... personal rant over, your best bet (and likely to get a positive resolution if you haven't cheated) is to use the 'forms' that is found here:
https://forums.ea.com/discussions/swgoh-general-discussion-en/cheating-and-appeals-process/10674104
Best of luck.