I should have thought that all people who have bought a Filser Mode S would be entitled to a full refund including fitting costs as the unit is clearly unfit for purpose...........
Better than that, they should pay for the cost of putting you in the position you would have been in had they not broken the contract, which a reasonable judge (I'm sure they all are!) might agree was that they should pay for you get a different unit from a different manufacturer supplied and fitted.