s.tax.claims

As u r paying service tax on Goods Transport Agency (GTA) and assuming it is applicable to u , the clarification to ur queries are:

1. 75% abatement is available on Service Tax on GTA, i.e., the calculation for the Service Tax will be

Freight*25%*applicable Service Tax Rate

2. The payment of Service Tax on GTA  is eligible for Input credit .

3. Service Tax on Telephone Bills, Commissions etc. are also in the nature of Input Tax, which can be adjusted while paying output tax. Since Service Tax on GTA is a input Tax, it can not be adjusted with another input Tax. If u r a manufacturer of dutiable goods, adjust these input credit with ur output duty payable.

Mr. Vibhash has explained well. 

If the ST on freight for every month is paid by the end of the month [ instead of 5th of next month] since credit adjustment is not there, the cenvat credti on the payment is available for the adjustment to pay the central excise duty along with the other services paid for.