If you have any technical issue please post in forum. Otherwise, if you have any pre-sale or order related query please mail to support@wpdownloadmanager.com . Again for technical support, if you are already using pro version please post in pro forum and free version users please post here
After purchase, if you see any delay ( very rare case ) in receiving confirmation email Please signup or login ( https://www.wpdownloadmanager.com/purchases/ ). Then go to orders page ( https://www.wpdownloadmanager.com/purchases/ ) and enter Order ID in textbox and click Resolve, then you will have immediate access to your download.
If you need additional customization on WordPress Download Manager or any type of custom support on WordPress you may mail your details to customize@wpdownloadmanager.com