User Activity

Do ebay have a problem with website as i'm unable to change P&P amounts on invices.Also there seems to be a problem with script.
Why are my sold items not showing in my sold summary
Can anyone help.I can't seem to be able to leave feedback for any of my buyers as an input error message keeps coming up whenever i try to leave feedback.I've entered all the relevant info but still get the input error message.
What can i do if a buyer says he hasn't received items when i know to well that he has.Even ebay sides with the buyer and has stopped the payment from my paypal account.