Service tax return rectification

1.You may adjust the service tax paid against service tax or excise duty liability.

2. You may also apply for refund of service tax mistakenly paid u/s 11B of central excise act 1944.(As made applicable in case of service tax vide section 83 of Finance Act,1994).Further limitation of 1 year to apply for refund will not be applicable in the cases where service tax is paid mistakenly.(KVR Const.2012).    

i m working at construction company. we have deposited service tax., now our party has cancelled invoice due to worked without purchase order. i can revise the service tax return  or not.