Some of your post is missing but I'll hazard a guess that you're probably clicking on "recalculate" after you've entered the amended postage. That poorly named button simply returns the invoice to what it was before you discounted it, so just enter your new postage prices and send the invoice without clicking on recalculate.
Thank you, yes I was pressing recalculate - agreed it's poorly worded, in fact the whole page is poorly set out. Thanks for your input, much appreciated.
