Will a parcel being shipped by USPS get delivered by Royal Mail in the UK?

I'm awaiting the delivery of my Saleae Logic. But looking at the tracking they attempted to deliver it to my work today, but for some reason they were unable to deliver. Nobody on reception seems to know anything about it, so I'm thinking they couldn't actually find the address (think big glass building in the middle of the city centre with it's own post code!).

I'm concerned that the fscktards at the Royal Mail will end up sending the bloody thing back to San Francisco.

What's the best way to get in touch with them? Preferably in the UK?

EDIT: Interestingly, from reading the dev blog it appears that Saleae have had loads of trouble with USPS especially overseas deliveries.