Defective lenses from Spec-Savers

Three and a half years ago I bought two new lenses Spec-Savers, Table View. Cape Town..These lenses have now become cloudy and defective. It appears the coating on the lens is disintegrating. The Spec-Savers assistant acknowledged that the lenses were defective but refused to repair or compensate me in any way saying there is only a 2-year guarantee. I feel this is grossly unfair and appeal to their sense of fairness to reconsider their decision.