Hey, if they said the last one was fine and now they want you to redo it, then yes, 'REDO -- RECHARGE'.
Question: did you have them sign confirmation of last design or request that they send a confirmation email?
I call it the blue line. When we come up with a layout for a client, it's not functional - just cosmetic, we show the client. If they like it and want to proceed they must confirm via email. We also make them understand that changes to the layout (other than text) once they accept the blue line will cost extra.
COMMUNICATION IS KEY! BE CLEAR - EXPRESS TERMS BEFORE YOU ACCEPT THE JOB!