Had the same thing happen on my third day with the GS, called BMW to see how much they wanted for a clutch lever.... $80.00 USD!?!?
Went into the garage and smoked a butt while filing the edge down, I will probably investigate the Wunderlich lever's at a later date (currently have some other farkle qued for purchase)... I have their 800GS tank bag which is extremely well built and designed. Don't think you could go wrong with the Wunderlich levers.