ShowIt - Non editable Robots.txt file?

Title pretty much sums it up, client is using ShowIt (with Wordpress integrated) and not only can we not edit whether a trailing slash is used or not (so WP blog was originally different to the main site, causing redirects everywhere) but we also can't edit the Robots.txt file, which means we can't disallow any tags, wp-admin files etc. Anyone any experience of this? Seems like a massive oversight. (And just another reason why I hate these overpriced drag and drop platforms)