Could you quote the § 19.3 of the N26 terms? I looked into the terms at the following website,
but I couldn´t even find this clause:
https://docs.n26.com/legal/small/en/account-terms-and-conditions-latest.pdf

Maybe the real reason wasn´t the transfer from Kraken, but simply that your account was pretty inactive
aside from receiving the Kraken transfer. And you incur certain costs for N26 if you don´t really use
your account, because they have to pay partners like Mastercard irrespective of your actual usage.