My phone thinks it has a failing media card installed?

My blackberry bold 9700 was from my work colleague. It may have been old but once a new housing case was installed it was working practically brand new. But recently its been thinking it had a media card. I was asked to repair this card I could not find within my phone. But in my phone's attempts, all my photo's, videos and music was erased. I cant download more music or record videos anymore but can take pictures. What can I do?