If you have kerbed the rims you can't expect Mercedes-Benz to pay for refurbishment even though there is other damage you did not cause. The worst alloys are shiny ones that are simply lacquered polished alloy. The slightest chip of the lacquer allows winter road sale saline solution through, and that oxidises under the lacquer. The most corrosion-resistant alloys are painted, preferably with several layers of VHT silver paint, before being lacquered, but you still need to inspect them regularly and touch up any chips or kerbings to prevent corrosion getting a hold.