Welcome to the forum. Odd. I have never come across this.
Try cycling through the trip odometer button to see if the correct mileage returns.
See what mileage is stored in the PCM or BCM? You may need a capable scan tool to see this.
The dealer service dept can't turn this instrument cluster odometer back. An authorized Chrysler electronics repair depot might legally be able to, but they would need recent documentation (like a repair order) that had the claimed mileage written on it.
It may be from a cluster malfunction that illuminated the '1' in the display? If the repair facility can prove this is what happened, it might help them to correct this.