If you "Reset" the phone (reboot means turn off and back on) then there is no way to get back the removed data. It is meant to wipe the device so any problems with software would be removed. I can't tell you not to try, it is up to you, and info on how to do so is below, but I can say it is highly unlikely that it will work in this case. It is meant more for accidentally deleting something, not after wiping a device.
While there is no guaranty that you can get them back. Deleted does mean deleted. There are a few apps/programs out there that 'may' be able to help you recover the data.
A few of the programs you could try would be... DiskDigger, MobiSaver, Android-Recovery and Tenorshare. They are all data recovery apps/programs. There...