Notice for demand against C form

Hello, we were an registered dealer under haryana VAT and transfer in GST when it was converted and all the returns and forms were summited in department on time. Recently they have issued an notice of recovery and say they have not received any forms against the returns which was filled and now they are demanding the demand money and we are currently not available in the same state we are in different state we went there only for business and after covid we were notable to continue the same as suffered losses. now we have the forms copy but not have the receiving with us and currently there is no one there go and officer is asking to send someone even we asked if we can send the documents via postal but he says we have to send someone physically to talk with them and I am not smelling something fishy as he may ask for money also which he is not asking over the phone. Can anyone tell what to do in this case and is there any why to submit the forms online as in site I did not find any option or should I email them or to any senior person. Please guide.