HDFC Bank — OTP not getting in Registered mobile no

Address:

Dehradun

Please be informed that i *** Bank Account No: NRE *********470 while doing net banking and while doing online transactions the OTP is not getting generated and unable to come to registered mobile no. ...***720
I have reported the matter to my NRE fund manager in Dehradun branch and also reported to the online customer care cell, but no one is unable to resolve the issue.
I am due to join my duty abroad where I need to use this bank account and ATM card and incase of this problem I will be unable to use this account.
Ultimately applying another bank for NRE account which i don't want to do it as its my old bank but if the things are not resolved i will be forced to go to another better bank, Please resolve this issue as it has been pending since the last couple of weeks.