Even though most customers in the EU are do not have to pay VAT, local regulations force us to charge VAT unless they have provided us with a valid EU VAT number. To avoid being charged VAT at all, please mail us your EU VAT number.
If your organization is exempt from VAT and your invoice mentions VAT, then send us your VAT number and ask for a new invoice.
In all cases, please mention both the number of your test-box and the invoice number.