Sandisk pen drives and memory cards - Duplicate material supplied without bill

I purchased pendrive and memory cards of SanDisk company from a seller approved by udaan . But it was duplicate and no proper bill supplied to me. I took this matter with the Authorize representative of the company and give some meterial to him for replacement/ refund . After so many reminders and even talking on phone of coustomer care person many times ,no reply recived from the company side. Now they are demanding Rs *****/- aprox for the wrong supply delivered. Since the material supplied to me was duplicate and without bill i am not going to release this payment untill I will not get proper replacement of my material which was handed over to the representative of the company . If forced, I will go to the consumer court for this matter that has spoild my image in the market