Pivot Table for Unpaid Invoices

Hi
Finance would like to identify unpaid invoices for schools visits. I have an existing Schools Visits dashboard which includes Order Paid Status, but I cannot add Payment Method as that field is not available in the Seats & Tickets cube. 

I tried to create a new pivot table using the Finance cube, which does include Payment Method, but then Order Paid Status is not available in the Finance cube?!

I'm thinking this should be a fairly straightforward ask, so am I missing something? Does anyone else have a way to report on unpaid invoices?

Many thanks
Best wishes

Dawn