Brake Fluid Leak problems of the 2010 Mercedes Benz C300

I brought my vehicle to Mercedes Benz for a rear tail light recall. When I picked up my vehicle the brake pedal went to the floor. Note: this was not happening prior to me dropping my vehicle off to the dealer. I informed the service manager and he drove my vehicle back to the mechanic. The service manager had me go to where my vehicle was on a lift. The service manager told me that the rear brake line on my vehicle rusted (metal line) out causing the brake fluid to leak out. Also, the passenger front seat sensor went and needed to be replaced. The seat would not move back or forward. In a previous complaint I filed today, I inadvertently put the wrong VIN number in my complaint. The correct VIN number is wddgf8bb3af406837. The previous complaint number is 11102627. My apologies.