Please Help: Service tax

A practising CS in his professional capacity provided a taxable service to his client relating to representing his client before any statutory authority in the course of proceeding initiated under any law for the time being inforce by the way of issuing notice, for that professional work "he raise a bill of Rs. 36000 12.36% service tax" but company refuse to pay service tax on that fees. So my question is whether the contention of company not to pay service tax is appropriate or not?