Why can't we get the right equipment the first time? member-owned-router-fiber-internet request

We signed up for Xfinity Gigabit Internet, but the equipment we were given appears to be incompatible with the service at our home.

Our home has a fiber ONU with an Ethernet connection, but Xfinity provided us with a gateway that requires a coaxial connection. There is no coaxial connection from the ONU to the Xfinity equipment.

According to Xfinity's own support article: https://www.xfinity.com/support/articles/member-owned-router-fiber-internet

It appears that an agent should be able to provision the service so that a customer-owned router can connect directly to the Ethernet connection from the fiber ONU.

The Xfinity stores we've been to both are confused by the situation and said they can't help us.

However, the chat support agent insists that a technician must come to the house and that we may be charged for the visit.

We're already three days without internet, and now we're being told the earliest appointment is another eight days away.

Can someone from Xfinity please explain why a technician visit is necessary when Xfinity's own documentation appears to describe a process for using a customer-owned router with fiber service? If this can be provisioned remotely, we'd really appreciate having someone who is familiar with Xfinity's fiber service take a look at the account rather than leaving us without service for another eight days.