I bought a new 4 GB micro SD card and it can not be read by my camera aor my mini DVR. When I put it in my laptop it shows up on my computer as an SD card, but when I try to format it it says There is no disk in the drive. I know the disk - brand new while still in the package was exposed to a strong magnet. Is this disk ruined now? Obviously there is no data on it, but is it fixable or garbage now? Thanks!