IMMUNISATION BILLING

I gave birth in january 2015 the 29th and ever since i have been taking my daughter for immunisations at the same hospital lesedi, pita pata and the past weekend i was told by one of my friends that she has never paid for immunisations for her son. Her son is now 3 years old and not even once has she paid paid for immunisations, i pay R300 everyime when i take my daughter for immunisation. I have been trying to contact pita pata but there is no answer on their their telephone,called the reception and asked how much is it for immunisations and the receptionist told me she doesnt know and that she will transfer me to pita pata instead the call cuts everytime when she transfers me. I NEED CLARITY REGARDING THIS, I NEED TO KNOW WHY IM BEING CHARGED FOR IMMUNISATIONS WHILE OTHER PEOPLE ARE NOT CHARGED!!!!