Hello, I'm TV Tech1 and I'll be working with you to identify and help you resolve your problem.
the camera will take photographs and store them on the internal memory
I had the same problem as you did with my camera. My SD card died on me, and I took some pictures that got stored in the internal memory.
Then I got a new SD card, formatted it, slipped it into the camera and took some more pictures. Unfortunately what I found out was that the camera didn't transfer the memory over to the SD card. In fact, it kept writing to the internal memory. I could see the pictures on the camera, but I couldn't transfer them to my computer, and the SD card wouldn't store any pictures at all.
It's got to be a design limitation on a lot of camera models including yours.
What did I have to do? I didn't have a mini to USB cable to see if I could transfer the camera's memory to my computer, I had been using the SD card for transfers.
But I knew I had to clear the pictures off the camera, then install and format the new SD card, and then the camera would place the pictures on the SD card instead of the internal memory.
So I sacrificed the pictures on the camera and deleted them first. Then I connected the SD card and did the format, and now it all works just like it did before.
I don't think you can get past having to delete the pictures on the internal memory.