Fixed Priced Contract Ended, left a good feedback and now client wants a refund.

Ok, I started to work for this client. I did everything they asked me to do. Followed their exact instructions to the fullest. When I turned my completed, I told them that if there was any questions or edits, let me know before ending the contract. The client told me that everything is fine, I did a "fine" job, paid me, and ended the contract. After 3 days, she cam in contact with me again saying to do more of work, do this and do that because I didn't do anything right. She said that I missed some information that needed for the work to be completed. The information that was missing wasn't given or stated on the job offer that she gave me when she hired me so why should I keep working for her? Now she wants to refund the money she paid me because I didn't do the job correctly. I don't think I should refund because I have done everything stated on the contract. The contract has ended, she left me an awesome feedback, paid me and now she's telling me to refund?

...and a closed contract is a closed contract. She's left you good feedback, so she can't now touch your perfect five, so you can just walk away and avoid her like the plague in future. Maybe message her one last time telling her in no uncertain terms how you have no intention of refunding anything and that the contract is closed. Keep it to-the-point, assertive and professional-sounding. If she keeps hassling you, file a complaint to oDesk, giving them copies of all messages and interactions (which is why it pays to keep all your words to her professional and considered). She sounds like a bully and a chancer - don't let her get away with it and don't let her stress you out. Send her the message and walk away (just me advice - others may say different...)