Email account compromised and unable to change password

My e-mail has been compromised.  The bot has accessed my contacts and has been spamming everyone for several days.

I've attempted to change the password with both yahoo and verizon, but it has not worked.

I've used the password reset utility on myverizon and this does change the myverizon password, but it DOES NOT CHANGE my verizon/yahoo email password.  My verizon/yahoo password remains the same.

How can I change my verizon/yahoo email password?