While trying to write a OS image to a SD card for my single board computer via the terminal, I ended up accidentally writing the image to one of my 500gb hard drives in my computer instead of the SD card. Originally the drive was NTFS formatted, now it has the contents of the OS image (Two partitions a fat16 that is 80MiB and a ext4 that is 465.66MiB). the command I used was "sudo ./format_sd.sh /dev/sdc" (The script I ran can be found here: https://github.com/avafinger/nanopi-a64-firmware/blob/master/format_sd.sh) I have tried TestDisk but it only recognized the partitions that were accidentally written to it. I'm running Ubuntu Studio 18.04.2 LTS.
Is there any way I can recover most or all of the files?