St Courier — Haven't received the product after one month

Address:

3, 362, Old Mahabalipuram Rd, next to Khadim's, Anand Nagar, Mettukuppam, Thoraipakkam, Tamil Nadu 600097, India

On 22/2 I had sent a courier from Chennai to Bangalore(consignment number:[protected]) on ST courier (courier sent from branch :MAA TPK). I haven't received the package yet. When I track using the consignment number, it shows that the item has been delivered. I tried calling to ST courier customer care many times and I got a response saying that the package has not been sent yet. It has been a month now and still I haven't received my package which is quite expensive. I am fed up with the customer care and I am going to move legally if I don't get a convincing reply and evidence by today. The customer service is not responding properly