how do I change an invoice amount

[quollmb]

How do I change an invoice after an item has been sold but not paid for yet.  I've tried numerous times to change the invoice prior to sending but it keeps reverting back to the original.

[digital*ghost]

You're only able to adjust the postage amount (and not by more than the P&H charge - i.e. you can't discount by more than the original cost of postage). The Recalculate button is poorly named and actually = revert to original, so once you've input the correct charge, either just hit send, or preview and if all is right, then send.