Sorry but if you didn't insure the delivery I don't see what you can do.
I'd never sell anything costing more than £50 even without a tracking number, letalone £200. Lunacy.
I hope you sort it out but when it comes down to it, tracked deliveries are offered for a reason.
Previously: 2003 Peugeot 206 1.6 8v | 2006 E90 320d M-Sport, 19" BBS CH, Full Ice-cold JL audio install, August 2010 Total BMW 6 page feature car. | 2003 Nissan 350Z GT Coupe 286BHP
Now:2010 E92 LCI 335d M-Sport