Missing content after browser crash - Roll Back

I was working with Prezi, and have about 8 hours of new work put into it.
The browser crashed, I reloaded it and it was a very old version which then saved over my recent content

https://prezi.com/60ygnv3a-nam/?token=c7aac5a756db6b9c99ad44b82d2d4435f2717a976bb027220b79d93ca86020c2&utm_campaign=share&utm_medium=copy

Roll back to Sept 25, 12:30pm ish.

Please HElp