Why my account has been flagged?

If you want a specific answer, you won’t get one. Brave has long said it’s their policy never to tell anyone what they specifically did.

While it’s not much of an answer, you might want to kind of read Why do profiles get flagged?

It depends on the response you got. If they said it’s been flagged and won’t be reinstated, then there’s nothing more you can do. That is them saying they investigated and have made a final determination. Essentially they are permanently banning you (at least that specific profile and ZebPay account) from being able to receive payments from Rewards again.

If they didn’t tell you it won’t be reinstated, then you would just follow up with them and find out what they need.