Hi Paul, thanks for posting! I apologize for the frustration and I will be happy to help!
Would you be able to let us know the brand and model of monitors you are using and the resolution that is being set within Display Settings?
Pending that information we would want to examine a log file from your system in order to help determine what may have happened. To help us do so please download and run our diagnostic utility PlugDebug --> http://plugable.com/support/plugdebug with everything connected. Please send us the file that is created on your desktop to our direct support email at firstname.lastname@example.org with “Ticket Number 168846” in the subject line and we can match everything up.
Given the frustration a return for refund is certainly not a problem if this is the route you’d prefer and I can reach out to you directly in order to coordinate and proceed accordingly.
Thank you for your patience,