Track and roller replacement
We unfortunately don't sell a replacement track that matches this part. We do sell a series of tracks that work in the same capacity, though. See our 47" long 23-270, 59" long 23-271, and 71" long 23-272, depending on what length you need. However the problem here is that, while they may work with all the same hardware on your closet door, they likely won't be properly sized to your carpet. Alterations may need to be made on that front so that it looks nice.
Your original track design is discontinued and to my knowledge is no longer made. Those three products I mentioned are our best options for you. I'm sorry that we aren't able to provide anything closer.