Today I created a Netlify account and tried to contact them via the contact form but it showed me the following error.
I already have a Netlify account.
So I sent an e-mail to support@netlify.com and it showed the same error again.
Hiya @cnktmp 
welcome to the Netlify support forums! 
I’m not sure why you are receiving that request did you verify your email after signing up?
Additionally, you are free to post your questions here in the forums! I see you are on the starter plan and we do not offer help desk support for customers on our starter plan.