My twitter account was suspended. I have emailed

never

Maybe some user type your email as his by mistake, if so the only way is to create a new account with a new email.
if that's not the case then maybe you deactivated your account by mistake or it was suspended, if so you have to wait for 30 days then try to log in again.
for further info you can contact https://support.twitter.com/forms

They should have replied in a week, because they haven't you should appeal again using this page.
https://support.twitter.com/forms/general?subtopic=suspended

To create an account:

1. Go to http://twitter.com and find the sign up box, or go directly to https://twitter.com/signup.
2. Enter your full name, email address, and a password.
3. Click Sign up for Twitter.
4. On the next page, you can select a username (usernames are unique identifiers on Twitter) - type your own or choose one we've suggested. We'll tell you if the username you want is available.
5. Double-check your name, email address, password, and username.
6. Click Create my account.You may be asked to complete a Captcha to let us know that you're human.
7. Twitter will send a confirmation email to the address you entered on sign up, click the link in that email to confirm your email address and account.

For more information visit, https://support.twitter.com/articles/100990-signing-up-with-twitter

Hope that helps!

twitter offers a way to reset your password if forgotten in the login page click forgot password and use your email to recover your twitter account once done check your email (even spam folder) for a link to recover your account

i dont think they will give you your account back because they are very strict to those who violate their terms.same has happened to my friend and his account was temporarely blocked by youtube.

Contact twitter support and ask them to retrieve your details.

i had experienced that also. facebook had suspended my account for three weeks. emailing facebook doesnt do the work because they have protocols for sanctioning account users of facebook who tends to "abuse" their accounts. all we goota do is to wait for them to lift your account sanction.

Did you give Yahoo any details after the initial suspension email? You may have fallen foul of a phishing scam, and the email may have likely been faked. In which case, contact Yahoo immediately, and change all your passwords.