Ecom Express — OTP issue

Its been more than 3 days and the company niether responding to my mails nor taking things seriously. They are telling they have send me an otp on my number. But i havent recieved any otp. I have explained and tried to talk with the courier boy several times but he says its policy. I told him to make a call so that i can talk to his executive but he always denies this. I have complaint about and mailed it to them but havent recieved any further replies from them. I tried to contact to customer care service but it always denies that my awb number is wrong and but when i try to track it says its correct and gives me all the details.