general problems of the 2000 Plymouth Voyager

My van (Plymouth Voyager 2000) stalled in the middle of an intersection. I was unable to start it and had to be towed in to an auto center. After a review, I was told that the tensioner unit that housed the timing belt broke into pieces. The shop called the dealership and was informed that they knew of the defect and has already constructed a replacement unit for the van. When asked if there was a recall on the defective part, they were told no. My husband called two dealerships and was told the same by both. "as of yet, there is no recall on the defective part. " I would have to pay for the replacement part. The total cost of the work done was $836. 77. I do not understand why I have to pay for a part that is known by the manufacturer to be defective.