how is it possible they have stamped the visa on 15 Auguest and decision made in Ecase on 18 Augest and it took 12 days that you have got the passport back .... :-[ :-[ :-[
Congratulations!! :D :D :D very happy for you!
can you tell us when you have submitted your passport and when you have got your passport and see your visa when the visa stamped in your passport .
thanks