INNOVV C5 Helmet Camera used to record Music Gig

Hi all I have been using the C5 with a SanDisk 64g class 10 SD card with the camera setting on 10 min loop, today I used it with loop turned off and my card is now un-formatable and my laptop tells me it's now corrupt. Anyone else had this happen, I called innovv when I got the camera and they told me the SanDisk card was fine to use with the C5.

After getting the new C5 i have to say it's a cracking piece of kit BUT i'm having trouble with the audio while i'm filming. The spoken work is nice and clear and crisp but i'm getting a lot of background noise that sounds like i'm in a fish bowl, i'm using the Innovv external mic and the DVR is in the inside pocket of my bike jacket, any hints or tips on how to cure this would be greatly appreciated.