Metro Police are the best people to contact about drivers breaking the law.  Phone them on 031-361 0000.  I am not aware of an email address.  They can also be asked to police 'hot spots'.

You can also contact the Durban North Station Commissioner, Sen Sup Gonya on dbn-north-saps@saps.org.za regarding criminal activity in your area.  He will pass the information on to his relevant departments. 

You are also welcome to contact the Community Police Forum Chairman in your Sector.