Body Corp Failing to Fix Apartment Defect (SA) - What Should I Do Next?

Hi all, can I get some advice from you about a Body Corp issue that I am uncertain about how to tackle?

I own a small apartment in a multistory building in Adelaide. During storm activity last December there was extensive water ingress into my bedroom with damage to the carpets and dampness in the wall (window was closed at the time). My carpets were covered by my contents insurance but because the window frame/wall was common property under my title (community title), I promptly inform the body corp manager. A builder sent by the body corp mentioned that the water ingress was from a defect in the bedroom window frame. Apparently, about 10 other units in the building experienced similar water damage.

I was initially told the damaged frame (and any water damage to the wall) would be fixed by the body corp manager. However, its been nearly 3 months and despite repeated calls, I still cannot get any indication from the Body corp manager about when (or if) the defect will be fixed. In the meantime, my soaked carpet and underlay were removed (since it was a health hazard) and my apartment now has exposed concrete flooring in the bedroom. Also, I continue to get water ingress every time there is heavy rain (3 times since the original event) and as a result, I cannot lay down the new carpet. Finally, after getting no response to my calls, I sent a formal letter to the body corp manager sequentially outlining dates of events and my concerns. I requested a formal response to this letter but I received no response from the body corp manager other than an email saying he will pass on my concerns to the management committee.

I am not sure what I can do here. Do any of you have experience in this situation in South Australia? Can any of you advice what I should do next? Any help would be much appreciated.

Thanks in advance.

PS Just to be clear - the window frame/wall is definitely common property under my title.