Tax code on order lines.

I disabled the Tax regime which migrated from 11i for an operating unit, then create a new tax regime and etc, there are three tax rules which I created as below:

rule 1. Ship from = China,ship to = China  and cost class<> Service then rate =17%

rule 2. Ship from = China,ship to = China  and cost  class = service then rate =6%,

rule 3. ship from =China but ship to <> china then rate = 0.

without any issue while for the tax setup and the tax also available for all transactions. now I  got one issue,  we are using  tax-group for financial options tax classifications of AR, if I defaulting the tax classification to rule 1  and it worked for all items not only rule 1 which I pre-defined. how to do to calculate the tax I defined in rules?