Compact Coolpix A1000 - Black + Nikon Nikkor Wide Optical Zoom ED VR 24-840 mm f/3.4-6.9 f/3.4-6.9

I received the camera in mid-January last year. From that day onwards, I have been fiddling with it almost daily. That way, I slowly and painstakingly got to know the camera. The user manual provided is very brief and not always clear. Due to the above, my response to this email has been continually delayed. I can now say that I have got to know the camera. However, it happens more often that photos do not end up on the memory card when shot and also other settings are not saved. Today I get the message " the memory card can no longer be used. My dilemma now is: Is it the camera or the memory card ? The memory card is brand new and according to the documentation compatible with this camera. The camera is "refurbished" , where possibly the above was the defect. Can you, via the supplier, shed any light on the matter? Kind regards, Math. (