PXD01ANI Problem

I tried to send this message over a week ago, but I haven't heard back so I'm sending it again in case I didn't do it correctly.  We have four TV boxes.  Three are fine, but one keeps getting a message that there is "no software to execute" for that Pace PDX01ANI box.  I moved the TV to another box and it's fine.  I moved the box to another TV and it gets the same message.  I checked your website and apparently it has happened to others and seems to require that the box be replaced.  We live in Amherst, MA and the closest Xfinity store is several towns away in Holyoke, MA.  I tried to find a direct phone number to check to see if they have a replacement box there, but all I can find is the 800 number which leads to dead ends.  Please let us know how we can get a replacement mailed to us or if you can find another way to get this fixed.  We pay over $330 a month for your services so we hope that someone can help us.  Thanks in advance for your assistance.  My email address is [Edited: "Personal Information"]