EEG Surcharge on Heavy Electricity Users

The Germans seem to be stuck on the question of how to deal with the EEG surcharge with their heavy electricity users. Why not set it up such that electricity users pay the full surcharge on the first X GWh per year, a 50%  surcharge on the next Y GWh per year and a base surcharge on all consumption above this. If you set up the surcharge apportioning system this way it would prevent companies from inflating their consumption in an attempt to avoid the surcharge.