Can a member of staff ask me why i have to pay hmcs court fees card at a paypoint outlet?

i went into my local spar to pay my court fees on the card the hmcs provided me and the lady behind the counter asked me why i had to pay my court fees, when i got the card in the letter it said that they are not aloud to ask this, but since then i have not been able to find conformation of this on the internet if you could tell me the in's and out's, or even a link will be great that you all.