Duped: Given my licence key away.......stupidly!

Hello there,

I think I have been the victim of fraud and have been duped into giving my licence key away for RekordBox DJ.

I listed my XDJ-RX2 up for sale as it is no longer being used, and I had someone phone up about it, showing interest.

The guy came round and asked to see the controller up and running (working) - but ran into problems with the USB ports not being recognised. I tried various troubleshooting and he said that it could be due to the version of Rekordbox I was using, and to deactivate and test on his laptop - which I did. He said that he was purchasing the controller off of me this wouldn't be a problem anyway

I couldn't get the controller to work (USB port issue) and the guy left. I did ask him before hand to uninstall-deactivate the licence for Rekorbox and he said he would, but after numerous phone calls to him over the last 2 hours since he left he hasn't done so - I now cannot contact him and I still cannot reactivate my licence to test the controller, as I have since got it working after doing a complete Firmware upgrade.

So as it stands this guy has now got my licence key for Rekordbox and there's nothing I can do to re-activate it on mine- surely providing evidence of my purchase this can be rectified?

I feel so stupid that this has happened - is there anything I can do? - I've contacted both the Pioneer and Rekordbox support addresses but thus far no reply.

Many thanks in advance.