Keep being bombarded with annoying e-mails

<p>I decided not to renew one of my website domain names and formally notified Register-IT.</p> <p>They nonetheless keep sending me annoying notifications that my domain name will expire if I do not renew the domain name.</p> <p>I have formally responded on numerous occasions but I still keep getting bombarded with e-mails from them.</p> <p>I am sick and tired of this badgering.</p>