Not meeting speed tier value

We recently upgraded our Internet speed tier from Connect to Superfast (200mbt/s > 800mb/s) and upgraded customer-owned modem from Netgear CM600 to Motorola MB8600.  Checked download speed with Ookla Speedtest w/ direct

modem > Desktop PC connection (Cat.7 patchcord) before and after switching modems: CM600 ~ 350mbts; MB8600 ~ 460mbt/s.  Tests were run repeatedly, after many reboots, etc.  Spent several hours on phone w/ Level 1 Support to no avail, and I'm totally done with that option.  It looks as though we're provisioned for the next tier down, "Fast" @ 400mbt/s, rather than our plan's "Superfast" tier.  May I ask for help from any of the Comcast employees on the forum who can expedite the proper provisioning for new modem per plan?  A an aside, I might mention that there is also a stand-alone Arris TM-822G emta modem for digital voice on the account as well, and that was disconnected while new modem went through setup and provisioning.

Thanking in advance for any assistance provided.