Returns a billing customer's invoices, payments and credit notes in a single statement. Invoice and credit-note totals and balances, and payment amounts and balances, come back as strings fixed to two decimal places; an invoice paid by card also carries the card's last four digits and type. Payment and contact details are included only for accounts billed directly. If one part of the statement cannot be loaded, that section comes back empty or null inside an otherwise successful 200 rather than failing the request.