Case C-200/14: Judgment of the Court (Second Chamber) of 30 June 2016 (request for a preliminary ruling from the Tribunalul Sibiu — Romania) — Silvia Georgiana Câmpean v Administrația Finanțelor Publice a Municipiului Mediaș, now Serviciul Fiscal Municipal Mediaş, Administrația Fondului pentru Mediu (Reference for a preliminary ruling — Principle of sincere cooperation — Principles of equivalence and effectiveness — National legislation laying down the detailed rules for the repayment of taxes improperly levied with interest — Enforcement of judicial decisions relating to such rights to repayment stemming from the legal order of the Union — Refund payable over a period of five years — Repayment contingent on the existence of funds received from a tax — No possibility of enforcement)