If you still haven't received you badge after completing C25K then send a message to LoraHU who will sort it out for you or see her message on Questions. (To message her select "message" from the top, then enter LoraHU as recipient, then go get your badge. Well done..
It is a pity that this can be so hit and miss but if all else fails "report" this message and then admin will also pick up your request. Not ideal but it works.