Does the phone say that any memory is being used up?
The reason I ask is because I once had an SD card from a camera which showed the pictures on the camera, but not on a PC (although the PC did recognize that there was a card and that memory was used, it didn’t recognize the files).
I was able to recover some of the pictures by uploading the folder to Google Drive. If you have an Android, and the phone at least shows the card, you should try to see if it can be uploaded.
Doesn’t sound like it’ll work, though. 🙁
I assume you already tried cleaning the contact point.
There is downloadable software, such as CardRecovery, which is supposed to help, but I’ve never tried it.
Hatzlocha.