Case C-19/20: Judgment of the Court (Seventh Chamber) of 29 April 2021 (request for a preliminary ruling from the Sąd Okręgowy w Gdańsku — Poland) — I.W., R.W. v Bank BPH S.A. (Reference for a preliminary ruling — Consumer protection — Directive 93/13/EEC — Unfair terms in consumer contracts — Effects of a finding that a term is unfair — Mortgage loan agreement denominated in a foreign currency — Determination of the exchange rate between currencies — Novation agreement — Deterrent effect — Obligations of the national court — Article 6(1), and Article 7(1))