Multi-turn user requests:
user: I have a fabulous universal travel credit card that I want to register. The number is 1432-7890-6543-9876 with a CVV of 321 and expiration date '12/25'. Oh, and save the name under 'Michael Thompson'. Register with access token 'abc123xyz456'. Additionally, I need you to set it up and then procure travel insurance worth $2000 for my family vacation, which should comprehensively cover the journey from Munich all the way to Guangzhou. We start off at the remarkable Munich Massive Megatrip on December 24, 2024. Fingers crossed for a seamless experience! booking id is insurance_12345
user: Once the travel insurance is successfully procured, I am at a loss remembering the aggregated expense involved. Could you retrieve an invoice for this insurance to ensure my financial records are precise?
user: During this adventure, an unexpected hiccup arose. Kindly notify the customer support service about this incident to guarantee that our case receives immediate attention, ahead of others.

Tools involved: MessageAPI
TravelAPI
Expected function-call sequence: TravelAPI.register_credit_card
TravelAPI.purchase_insurance
TravelAPI.retrieve_invoice
TravelAPI.contact_customer_support
TravelAPI.book_flight
MessageAPI.send_message
MessageAPI.delete_message