Who to contact at AT&T to upgrade homebase service from 3G to 4G/5G, ie: ZTE USA Z700A

We'll be happy to assist you with your upgrade @huntsharp.

We see that you're interested in upgrading your wireless home phone device in anticipation of the 3G Sunset. Just to be clear, is the ZTE USA Z700A the device you currently have or the device that you're looking for? 

If this is what you currently, then you're already good to go, because the Z700A is on our list of compatible devices that will still work on our network after the shutdown. 

If you have a different device, while the Z700A isn't currently available on our website, any of the devices listed under the Wireless Home Phone section of that list will work for you. 

Please let us know if you have any additional questions; if so, we'll be delighted to assist you. Thank you for reaching out to our community. 

Darais, AT&T Community Specialist 

I purchased an apparently unused Z700A on line because ATT didn't have any per the Email I received "they flew off the shelves", there was also no reference to alternatives or when future stock would be available. I would like to be ready for the change.

Printed the User Manual from ATT HOMEBASE product support page and have read it to my ability.  Have a Nov 10 appoint with ATT Santa Rosa Business service office.  Just as soon avoid 70 mile round trip if I can get ATT technical support by voice phone to make the switch from ATT Home Base 3G device to ATT 4G device.  Need Phone number to call for HOMEbase support.  It seems ATT has abandoned its HOMEBASE products as the web sites referenced in the documentation go to generic ATT sales pages that do not have Homebase products listed.

Thank you for reponding