I don't know what happened to the phone/card, but here is my advice:
* don't use the card - anything you do write on there might overwrite the pictures
* get a microSD reader for a computer. Quite inexpensive.
* plug the card into the computer. Can you see the pictures? If so, back them up to the computer.
* If not, use some file recovery software (Recuva is often recommended for Windows, and is free) and see whether you can recover the pictures from the card.
If they are on a microSD card, as the title suggests, this should work (as long as the card hasn't been so corrupted that the computer can't read it at all). If they are on the internal storage of the phone it's much more difficult, but also less likely to happen.
It's a good idea to keep anything important backed up. MicroSD cards do sometimes fail, and phones break or are lost.