If I may suggest, perhaps wait for a few more days as per what Kirito89 explained on the screenshots below? That the account and data removal happens gradually, with the account being banned as the first step. I believe this is due to wiping an account is not as simple as clicking a button. They need to dissociate the account from any data and transaction stored in their database.

Rest assured that DuckDice is more than compliant to GDPR data removal, as there was a neighboring case that actually got too long and too complicated than necessary because the player requested data removal and DuckDice did exactly that, wiping it clean. One year later, the player requested some verification of provably fairness and his record, which can no longer retrieved due to the purging.

So... yeah, maybe few more days while they gradually burn anything related to you from their database?