From where can I get an application form?
Interested applicants can get application form either from the reception area of the HR department (2nd floor of Council and Senate Building Anastasios Leventis) or form this webpage (look for application).

When are the offices of the HR department open?
The offices are open from Monday to Friday between 07:30 and 14:30 and Thursdays between 07:30 to 14:00 and 14:30 to 18:00 pm. During June/July and August offices are closed on Thursday afternoon.

With which person would I have to come to contact with to solve and complaints or problem I may have?
You can contact the officers of the office of the HR department directly (look for the services organizational structure).