@auhsojsa What do you mean by ‘fully deleted’ ? How did you attempt to find them?
I certainly believe you didn’t see them on the file system when you plugged the camera or card into your computer. But that by itself does not mean the picture data are gone from the card. It just means there is nothing in the directory pointing to the picture data.
Also depending on what the manufacturer means by ‘reformat’, they might not be gone from the card following that – almost always ‘reformat’ means the visible directory is wiped clean and the space is tagged available in the card’s internal allocation charts. In which case nothing has overwritten the picture data out on the sectors and it’s still out there on the card, a recovery program can find those.
Sometimes there will also be available a ‘deep format’ on a camera, for initializing a new card when you first get it, that sets up the sectors and puts data patterns on the storage space. In this case the picture information is overwritten and is not recoverable by a recovery program. If it is extremely important and you are well-connected you could get some scientists with a scanning electron microscope to analyse the structures which can reveal the previous values of cells. This is extremely tedious and expensive, probably only the three-letter agencies would do something like that.
This is the way our computer file systems work in general, including mem cards used in cameras. That’s why something like Norton file recovery programs can work, the directory says it’s gone but the data are still out there in the sectors. This is also why it’s advisable to do a ‘deep format’ of your hard drive, or destroy it, if you are discarding a computer. Snoops can fairly easily recover any file information that has not been overwritten.
Also I know file recovery from a camera card can work. While on a vacation I took a lot of pics one day, filling the card. I thought I had uploaded my whole card of pictures, but something went wrong. I ‘reformatted’ clearing out all the pics on the card. The next day I (fortunately) took a lot less pics. While reviewing them at the end of the day I noticed the previous day’s pics were missing. I used another card for the rest of the trip and when I got home I used a recovery program to retrieve all the pics that had not been overwritten the next day.