The WebAssist Surveyor links are all messed up - you should not have been directed to the SiteAssist 'Buy' page. From what I have tried, there is no way to buy 'Surveyor' at the moment until WebAssist correct the site structure.
The site map can't be dynamically created with SiteAssist. You should be able to claim a refund for that, and buy Surveyor once Webassist correct their mistake.
You could write to email@example.com and ask for a refund.