Hi Ellie1980 and welcome to the Q&A Forum!
It's really difficult to say why your camera is holding so few photos.
My first recommendation would be to reformat it, but it seems you've done so and it doesn't work. Make sure you're reformatting it in the camera, not on a computer.
I highly recommend you call the camera or card manufacturer tech support to see if they can suggest a permanent fix.
You may also want to try a progrm such as Memory Card Safe Eraser, which is free. If you download and try it, make sure to carefully follow the instructions of the developer and read any disclaimers at their site.
You can read about the program here:
http://www.artplus.hr/adapps/eng/dpr.htm(scroll to the middle of the page)
They say that you must FORMAT the card in your camera after cleaning! Evidently, the program also wipes out important information required by the camera.
Reformatting in the camera restores the information.
If nothing works, you may just have to buy a new card. Fortunately, prices have dropped in many countries.
Let us know how it goes.
