Case C-71/12: Judgment of the Court (Third Chamber) of 27 June 2013 (request for a preliminary ruling from the Qorti Kostituzzjonali — Malta) — Vodafone Malta Limited, Mobisle Communications Limited v L-Avukat Ġenerali, Il-Kontrollur tad-Dwana, Il-Ministru tal-Finanzi, L-Awtorita’ ta’ Malta dwar il-Komunikazzjoni (Electronic communications networks and services — Directive 2002/20/EC — Articles 12 and 13 — Administrative charges and fees for rights of use — Charge applicable to mobile telephony operators — National legislation — Method of calculating the charge — Percentage of the costs paid by users)