You can not edit an ad that has already been published.
If you make a new order later with the new changes, you will only create duplicate campaigns and you will be invoiced for both.
If you want to change something in your ad, contact Adfenix Support as early as possible. We will then cancel the campaign so that you can publish a new one with desired changes.
Always preview when publishing your ad, double-check that text and image are correct before you press publish.