The German term is Karton, which is 10 packets.
The text implies that you gave your Bank information and that the dutch tax office would book it from your account if no payment arrived.
Generally older Account numbers are the base of the iban number, with an added country and bank information. So the Dutch tax office will know how to book it if they truly wanted to.
If it has not been done by now, it may have been 'lost' somewhere inside/inbetween the (very deep) realms of the corresponding buroracicies, so either it will never turn up or it will suddenly turn up in 10 years.
Not paying a customs duty is not a crime (Verbrechen: 12 minimal months jail without suspension or money fine), but a misdemeanor (Vergehen) .
It is such small fee, that in general such things are forgotten or are determined not worth the effort (Verhältnismäßigkeit der Mittel).
If you are very unlucky a bored Official, driven crazy by his over eager apprentice says : 'work through that dusty pile of unfinished offenses'. Then, of course, you are sunk since the apprentice will wish to prove himself.
It is possible that after sending it to the Dutch, it was promply forgotten by German customs and 'lost' by the Dutch, since for them there is no gain.
Don't let it bother you, sleeping well is more important than worrying about this affair.