Parallels Desktop 11 with OS X 10.8.5

I have purchased and downloaded an upgrade version of Parallels Desktop 11.
My system is a iMac with OS x 10.8.5 with Parallels Desktop 10.
The upgrade can not be installed, gives the message 'OS x 10.9 or higher ' required.
What shall I do?
f.kilger

 

Hi, we would like to inform you that Parallels Desktop 11 does not support Mac OS X Lion 10.7 and Mac OS X Mountain Lion 10.8 as host OS.
So, you can upgrade to the Mac OS x 10.9 or 10.10 or ask us for the refund according to the Parallels Desktop Return policy.
If you would like to get a refund please let us know.