Rob Shaw

I make audio equipment for DJs and need to send units to the EU for journalists to review and test. I have done this a few times and always end up having to manually intervena and get charged incorrectly by wither UPS or DHL. What is the correct process for shipping a unit to a reviewer for a period and then getting it back. Surely there i s a method for this that DHL and UPS can understand. Any help gratefully accepted. Rob