Gopro battery life (hero3+black)

Not sure if this is normal or not but:

Charged the gopro on Thursday night and unplugged in the morning before heading to work, and on picking it up this morning the thing is dead? I know it was completely off and not in any sort of standby mode was on, I don't use wifi either,

Is this normal or should I contact the seller for replacement/repair?
 
I wouldn't have thought that was normal at all. When mine has been fully charged I can leave it for weeks (switched off) and it will be fine when I come to use it. There could be a fault with the charger or the battery??