Service tax is apply on rupees converted from foreign bank?

Hello,

I am having IT outsource company. I have a client in US and I dont know how but I got his every transaction in Rupees. I did not get a remittance notice and those transactions were not considered as remittance. When I investigate I came to know his bank in US is converted that to rupees and through NEFT, it transfer to my bank account. 

I got notice for those transection.

What to do?