Trade-In Challenge

In May I traded in my old iphone. In June I received an email advising: "Before we can process your trade-in, your device needs to be properly prepared. This means turning off Find My on the device you’re trading in. Please reference the link below and use iCloud to remotely remove your data and reset your device. Prepare your device Once this step is complete, we'll continue with your trade-in."

Upon following the instructions, I can see that I had already completed this step before I traded in my old phone. The old iphone is no longer listed in my devices in my apple account, on any device.

I cannot find, anywhere, an email address to contact an apple expert to resolve my challenge. Please can someone help me with this challenge. Thank you in advance.