DTDC - Package not delivered

My package B******** was not delivered and when I complained case no ******** still they haven't responded to this. It was the mistake of the delivery guy who told he deliver it the next day and it continued for three days and finally, he told sir your package had returned back. When I tried to contact the faculty none of them responded. I tried to complain them through the mail but still, there is no response. None of their feedback system or complaint system works. They told they will get back to me and it's like more than a month they haven't.