401 STOP IT

[Kosmos992k]

this means that your card is blocked from the site for the next 24hrs as some sort of safety for your card i think

This is the answer, and the worst thing is that when you retry and fail, it resets the 24 hour timer, and if I remember correctly, it extends to 2 and then 4 day blocks. And there isn't much Customer services can do to lift the block early.