Is my unemployed wife entitled to GKK health insurance in Austria?

Hi, I have been working in Austria(Graz) since December 2012. When my wife came and found a flat, then we went to GKK to enroll her in the system in order to have health insurance. She was unemployed and she had to be covered by my health insurance. But from that time point until now, GKK draws from my bank account an amount of money for my wife's health insurance.

The question is that I know 2 friendly couples, which there is no such a situation, that is the man does not pay for his wife and the last is fully covered by GKK. I have to mention that both couples have children. Did I have done something wrong at that time when I went for my wife's registration in GKK and I miss something in the "translation" with the officer there?? Thanks in advance, Vasilis