In the event that you are processing large amounts of data to the extent that the REST API is unsuitable, you may be elligable to obtain direct database access to your data.
This provides a direct MySQL or ODBC interface to your data, which can include call records, charge lines and message history.
Please note that access is typically only provided in circumstances where 300,000+ daily records are being processed. Database access will require an on-net service for connection such as a Cloud or Co-located server, or a suitable connection.
Please send an e-mail to firstname.lastname@example.org to request access.