hi, i registered another id by mistake. please advise how to deregister

I registered to weekly plan by my email id and next time by mistake registered from another email.  Anybody can do that mistake because all that it takes is email id and password and it registers or logs-in.

Now I am not sure how I can de-register.  Can you please advise.

the email that I want to de-register is **********

Thanks,

Venkat