Can't remove a computer and/or purge backup file set

[Windows 7, serv pack 1, 64 bit, PC, IE9 v. 9.0.8112.16421, Norton 360 v. 20.2.0.19]

 

Backup says I'm using twice as much online backup space as my backups can account for.  Backup says I have two computers with backups online, which would account for the double data dose.  (One of the computers and attached backup is probably an artifact left behind after two episodes of uninstall/reinstall carried out by chat technicians.)  As I understand it, if I remove one of the computers (the one with an older backup set), the extra backup files will go away along with that computer.  Thing is, the "Home Page" for Norton Online Backup is supposed to provide a "Remove a Computer" option.  It doesn't.  An option might be to Purge the older file set, but the Purge option is missing when I select "File Options" for either of the computers; options offered are "Download a File" and "E-mail file links."

 

Any recommendations gratefully accepted.