I know this, but am in two minds whether to ask my bank for a refund because I can see this causing all sorts of problems about then being in arrears with the payments even if I ring them up and pay the correct amount by card.
As suspected, too much has been debited from my account, looks like they have charged a full child price for an under 10.
This could of so been avoided if they wrote to everybody telling us what the new amounts would be