How can I completely delete my 160by2 account?
According the FAQ - you just need to send them an email along with your mobile number requesting they close your account.
How do I close my 160by2 account?
We’re sorry to see you go. Please feel free to let us know your user experience on 160by2 or any issue due to which you chose to close your 160by2 account on our feedback page. You can close your 160by2 account by sending a mail requesting to close your 160by2 account along with your mobile number registered with us to firstname.lastname@example.org.