The term "mug" immediately comes to mind - although if he'd been "invited", maybe the company should have made it clear they weren't actually in Istanbul but in a complete sh1thole thirty odd miles away - one of who's claims to fame is that they are twinned with some dodgy city in Somalia.
For the record, yes I've been to Gebze on several occasions and consider myself neither Gebzieist nor Somaliaist (spelling might be a bit out there!)
JF