Abandoned Checkouts contact information from Admin API

[Patriot2]

I am trying to get abandoned_checkout data using Shopify API. But in the billing_address and shipping_address objects I only get the fields province, country, company, country_code and province_code. There is no first_name, no address1, no city, as stated in the documentation. Why is this happening and how can I get full information about the user who left the abandoned cart?