Membership Upgrade Buttons Not Showing

Hello been loving using the plugin so far but we've got a bit of a problem with it on a site we're building.

We've created several membership levels, one free, one paid and one that will be used for when users post content. When a user goes to the account page there is an option to upgrade to the subscription level but the buttons aren't showing. Below is a screen shot of what I'm talking about.

What do I need to fix to get this working?