my seat started on fire

I travel for work. I turned on my car and started to drive and I smelled something burning. My friend was in the passenger seat smelling it too. All of a sudden I turn, and my seat is on fire behind me and is filling up my cabin with smoke. I quickly turned off the heater but the seat remained hot. and smoke was pouring out. I quickly pulled over! Thank GOD I was not on a busy road at the time. I looked down and my sweatshirt was burned. I have not looked into the cost of this yet. Mercedes should be recalling these seats. I see many people on here have this very complaint. I will NOT be buying a Mercedes again!