It depends... I do not know if you already have CAF before September 2013. If yes, I do not know if you can have the CAF for month 9 10 11 or not... It might be connected.
If not, you cannot have the CAF for month 9 10 and 11 because CAF starts from the month you apply instead of the month you moved in.
When you applied, you already moved out, right? If so, you do not have CAF. If they ask you to give back the money, it is correct.
All the answer above comes from my own experience, please just have a look and do not blame me for any reason...