The US tech giant Apple is “disappointed” with a ruling by the European Union’s highest court that the company must pay €13 billion ($14.4 billion) in back taxes. In 2016, the European Commission ordered the multi-billion euro tax payment, claiming the US company had underpaid taxes due in Ireland. “The European Commission is trying to retroactively change the rules and ignore that, as required by international tax law, our income was already subject to taxes in the US,” an Apple representative said. In the lengthy legal dispute, Apple had filed a successful complaint with the EU’s General Cou…