He's not being racist. My Dad is a security manager for Royal Mail and they have exactly the same problem there. Its not because they are immigrants that they are stealing/loosing mail though, its because the company is trying to make a quick buck by using agencies who don't do their job properly to employ dishonest people. Immigrants just happen to be cheap, so therefore make up the majority of the agency-employed staff.
Hope all this gets sorted in due course anyway. Even if it is the company policy of parcels2go to take up any compensation claim with the seller, their customer service has been poor at best.