Unbelievably bad customer service

I bought a Win 7 Inspiron 3847 on 11/03/2014.  In July, 2015 I started to have HDMI problems and on August the system refused to start.  Dell sent out technicians 5 times to replace various components, to no avail.  Finally on November19  Dell agreed to replace the system (by then out of warranty).  The replacement is Win 10 and after a couple of weeks I realized that the OS had not been activated and the product key it came with is "in use by another computer."  I called Dell to obtain a valid product key and got the out-of-warranty service group.  I explained the situation and they said I should talk to the in-warranty group because this is a continuing warranty service issue.  Sounded right, so they transferred me.  After a half hour with the in-warranty group they said I had to talk to the out-of-warranty group because the warranty had expired.  I couldn't convince them that this was a continuing warranty issue and they even refused my request to speak to a supervisor, saying it wouldn't do any good -  so they transferred me back to the out-of-warranty group!  Same thing all over again!  They transferred me back to the in-warranty group.  And of course the in-warranty group said I needed to talk with the out-of-warranty group.  I insisted on speaking to a supervisor at which the rep just dumped me back to the out-of-warranty group.  This is now almost two hours being bounced back and forth.   My demand to speak to a manager was honored this time.  Well, now a tech is scheduled to call me tomorrow.  My expectations are not high.