Helpline of NSDL

Dear all,

I had called on NSDL helpline for a query relating to TDS return. The executive was unable to answer my query and I requested to transfer the line to senior. My call was placed on hold for 58 minutes ; on and off the executive answered and said that senior was not available and he was busy on another call. It was frustrating, the senior was avoiding the call for sure. Isn't there any system in place where we can complain about this? I am sure many of us must have undergone similar situation for lesser or longer time.