I have an issue with the integration between appointments+

Hi
I have an issue with the integration between appointments+ and Marketpress which has not
been addressed.
Although I have set everything up correctly, the buy now button for the appointment fails to work.
Vaughan was looking into the issue but I haven't received any updates and need to make a decision to scrap this plugin or not as my client is fed up waiting.
I can't find an alternate method to contact anyone for support...
Walter