Issuing you with a refund would not be a problem but I am still willing to try to help you out if you like.
First of all, a few further questions:
(1) At what point in the process do you get stuck? It is when trying to upload the gallery files or when entering the embedding code?
(2) Do you have your own web space on a regular web server or does Yahoo! SiteBuilder provide the only web space you have?
If you have your own web space on a regular web server, then you should be able to upload the gallery folder using an FTP program such as Filezilla or through your web host's Control Panel (web browser interface).
If you do not have your own web space on a regular web server and cannot upload your gallery folder using the Yahoo! SiteBuilder interface to the web space they provide, you could host your gallery with a file sharing service such as Dropbox.
You could upload your gallery folder there and use an <iframe> in your Yahoo! SiteBuilder page to embed the gallery.
Just let me know if you would rather have a refund and I will contact you directly via email. Thank you.
SimpleViewer Support Team.