Do you know of anywhere to purchase one?

You can't buy one. You either repair the existing one or you make a new one. XYZ sells very few parts. They expected their customers to send the machines back for repairs and not be willing to do the repairs.

In very rare cases they have shipped new cable but it requires you to give them certain information that you no longer have since you flashed to Repetier which voids your warranty. If you could talk them into one it would still take a month to get it.