To find out the details for the agency(s) involved in your booking, go to:
Booking Requests
Search by the ShipTo number (If the booking was not done by yourself, switch the dropdown to All Bookings)
Click the correct tab (e.g. Confirmed if it's a confirmed booking)
Select the right booking and it will open up the booking details
Scroll down to see the Agency contact details in the Contact & Stakeholders section.