urgent clarification please

[o55r]

Applied Tier2 visa on 28/08/2012 after refusal of tier1 extension on 30/07/2012
biometrics: 18/09/2012

decision letter with visa refusal on 17/01/2013

reason is overstayed more than 28 days

but this new rule started from 01/10/2012.
I ma confused about the decision by case worker how my application is effected when I applied before the new rule i.e., on 28/08/2012

Please advice urgently

thanks in advance for reply