POP3 not working: User already specified

POP3 not working: User already specified

I am able to access the webmail, but I am not able to access my email via POP3. I never changed the configuration or the password. I receive the following error: User already specified.

I already contacted the phone support they told me they would fix it, but until now nothing is working yet.

Also I am not able to login in the support Center. I tried all my logins. Nothing worked! Can anyone explains how I can create an account on the support center, so I am able to submit a support request there?

Thanks