Hey Wfreij, I'm not sure how one goes about proving that you are a dependent of your EU familymember (dad).
Perhaps there is something in the Schengen visa handbook, which has an entire chapter in EU/EEA applications made under directive 2003/38. You can find the handbook here:
http://ec.europa.eu/dgs/home-affairs/wh ... dex_en.htm
As for direct applications, an other handbook (which explains the rules layed out by the visa code 810/2009)says:
4.4. Direct access
Maintaining the possibility for visa applicants to lodge their applications directly at the consulate instead of via an external service provider implies that there should be a genuine choice between these two possibilities.
Even if direct access does not have to be organised under identical or similar conditions to those for access to the service provider, the conditions should not make direct access impossible in practice. Even if it is acceptable to have a different waiting time for obtaining an appointment in the case of direct access, the waiting time should not be so long that it would render direct access impossible in practice.
The different options available for lodging a visa application should be presented plainly to the public, including clear information both on the choice and the cost of the additional services of the external service provider (see Part I, point 4.1).
This handbook can also be found on the before mentioned page. There you can also find contact info if you wish to sent feedback to the EU Commission (Home Affairs department) about embassies who seem to give people a hard time.
Also, your applications should have been dealt with ASAP, and at the longest 15 calendar days!! You may wish to contact the embassy and politely ask what the *** is going on (incompetence, not wishing to help you, mistakes by them, ... ?).