I cannot upgrade my phones due to erroneous "You’re over the total number of lines available to you" message

I have seven active lines on an account that can max out at 10. I am trying to upgrade two of those phones and get an error message when I add an upgrade to may cart.

So, to be clear, I am trying to upgrade a device(s) so not even add a line(s). But even if I was adding line(s) I would have three to spare.

Who can intervene and clear out whatever "cruff" is in my line count so I can upgrade online?