Excess payment of service tax

I have made the excess payment of service tax of Rs.500,000/-.under information technology software services under RCM on import services, but since we will not be taking such services in future so same can not be adjusted, Whether can i avail the cenvat credit on the basis of RCM challan (I don't have the copy of vendor invoice against the same) or can be adjusted against the liability in another service category in subsequent months?