Website builder

It is very annoying that everytime I open my email account there are so many messages selling different kinds of drugs or medicines. They are sending these messages through the feedback form I set up in my web site using site builder. The message contains hyperlink to several sites. I deleted already the feedback form but I still received the same spam in my email account. I already changed my password and even removed my “contact us page” where the feedback form was previously located but I still received spam everyday. It is very annoying and stressful when you see plenty of junk mails in your inbox and you have to waste your time deleting it. Please help me how to stop this thing. Thanks.