Steve,
You are correct mate, php files are most of the time encrypted but developers are normally very wise and the functionality in their php file that they create that does the job is normally done in such a way that the .tpl can control the way the PHP functions unless of course they did not think of an IF when the mod was created. Do I understand this correct?
This particular mod has a permission_templates.tpl file but then again I was an A*** because all I really had to do to sort my issue was to go to Membership levels and create any other membership apart from "Fulfilment staff" as the mod only appears to be working on "Fulfilment staff". Any other membership level you create has got all rights same as provider - This would have been handy to have known in advance