Clutch slips

Hello, I own a Mercedes W202 C220 and have renewed the clutch here. Speak of everything except mass swing wheel pull-out plate and friction disc. However, it slips nevertheless and has a bad pressure in the pedal. It can be pressed very simply as if there is no resistance, as it separates but drives the car. Only at higher speed it slips again. And according to Mercedes-Benz, the clutch is no longer manufactured. What should I do?