Multi-turn user requests:
user: It seems I booked my flight from Rome to New York without considering travel protection, especially given the uncertainties of winter travel. Would you assist in registering my new credit card, with access token 'abc123xyz' and card number 4012888888881881, expiring in December 2028 and a CVV of 465, to facilitate the purchase of a comprehensive travel insurance at the price $200 for this journey? My last name is Smith, first name is Michael.
user: I need to verify the specifics and total costs of the travel insurance and booking I recently arranged, as the details escape me at the moment. Is it possible for you to provide me with the invoice linked to the insurance purchase?
user: I’ve encountered some problems requiring immediate help regarding my upcoming trip to New York. Could you facilitate fast contact with customer support to address these insurance-related issues that haven’t been resolved?
user: The response from customer support didn't resolve my issues, and I'm quite frustrated with the assistance I received. Would you mind drafting a formal complaint titled 'Unsatisfactory Customer Support' outlining the shortcomings of their service? My ticket username is msmith, password is SecurePass123. Left ticket description as empty string.
user: I’ve reached the decision to cancel my New York trip due to unforeseen personal circumstances. Could you proceed with the cancellation process as soon as possible?

Ground-truth function call sequence:
TravelAPI.register_credit_card
TravelAPI.purchase_insurance
TravelAPI.retrieve_invoice
TravelAPI.contact_customer_support
TravelAPI.cancel_booking
TicketAPI.create_ticket
TicketAPI.close_ticket