Garage and water flows

Hi All, from NSW and am new to this great forum to help find answers…I too have water flowing through my garage. It is a parking and garaging area under a slab that has a garden above, and water enters through the double brick wall of the corner wall – we have had a waterproofing guy have a look and there is no vent to the garage either – he is not sure why the vents stop at next door’s garage when built. Apparently is odd from when built. So when it rains or when the garden club leave the sprinklers on too long we have water entering through garage edges of roof down walls , flows across garage diagonally to exit and flow to drain in carpark area outside garage.  Our boxes are wilting, spilling contents to floor though on raised shelving, possessions are becoming mouldy and very very musty smelling. So, I need some help here – is there a strata law/ guideline I can  cite when approaching my OC formally ? Responses so far when verbally opening subject range from: 1) ‘oh they built the floor like that so it would drain out – is meant to be like that’ 2) ‘good luck, all are same’  – not true – as strata minutes show repairs to wet ingress over the years to 2 others,  & asking around none currently have same problem & it was originally built to be dry. Am hoping I can persuade OC to repair with solid argument backed by strata NSW facts .  To act on waterproofer’s solutions – soon. Thank you (originally posted on another thread – garage water ingress  – but politely told to start my own )