I live in Iceland.
Iceland in not in the EU but is associated with the EU through a contract called EEA / EFTA.
I just bought "1 x Joomla! Extensions - Professional Subscription" so you owe me 16,56 Euro.
For you this is export as I'm not using this product in your country, and you should not be charging me VAT or Sales tax.
If you have any questions about this issue, talk to your tax authorities.
Please let me know how you want to return my money.