Further adding to the mysterious issue, I just logged into iCloud on my mac (safari) and non of the said corrupted videos are on iCloud, my phone says they are, they are physically on my iPhone camera roll too.
I read on another forum about transferring the videos to a PC, I did this and the video file is 0kb in size! How did this happen? That's game, set match, the file is GONE unretrievable, doesn't even exisit anymore to be fixed in the first place! I'm so furious with Apple, this is ridiculous!
I spoke to Apple on the phone and the rep continually tried to blame Snapchat, I let him know it couldn't have been snapchats fault because the videos were playing and saved to my camera roll for a good week, it wasn't until I back up to iCloud that they no longer work. I'm devistated, to add insult to injury, I actually pay iCloud for extra storage.
Done with Apple!