By Maria Ward-Brennan Four of the UK’s largest mobile network operators have been hit with a class action lawsuit, over allegations they used market dominance to overcharge customers. The class action was filed to the Competition Appeal Tribunal (CAT) against Vodafone, EE, Three, and O2. The case alleges that the companies have been abusing their dominant positions in the UK mobile industry by charging a ‘loyalty penalty,’ in which long standing customers were overcharged for handsets beyond the end of their contractual term. The claim alleges the mobile operators have overcharged on 28.2 m co…