User turns:
user: I'm planning a journey from Los Angeles to New York on the morning of April 15th 2024, preferring to fly business class. Arrange this flight using my pre-linked credit card with id 'card_123456789' and access token 'abc123xyz'.
user: With my flight now secured, I need to review the invoice outlining the costs involved. Retrieve that invoice for me, please.
user: There were hiccups during the booking process. Reach out to customer support and detail the challenges I faced.
user: Loggin in as USR001 for messaging. Once you've reached out to them, please brief my colleague Catherine (id='USR003') on the situation using my sender id 'MichaelTpss', message to send be 'Update on flight issue and customer support contact.'.
user: Finally, compile and present all the responses sent following the communications regarding the flight issue.

Involved APIs: MessageAPI
TravelAPI
Ground-truth function call path:
TravelAPI.compute_exchange_rate
TravelAPI.get_flight_cost
TravelAPI.book_flight
TravelAPI.retrieve_invoice
TravelAPI.contact_customer_support
MessageAPI.send_message
MessageAPI.view_messages_received