Oh, go on. Can't you just let me off the whole amount?...
Dear Mr Green,
I wanted to let you know of a problem we've identified with your July credit card statement.
When you look at your statement, you will see it says a 'payment is not required this month' which is incorrect.
I'm sorry for this mistake and I hope it won't cause you any inconvenience.
Lloyds TSB Bank plc