Who owns the tiles on my walls?

Who owns the tiles on my walls, and who has tro pay for their repair/ replacement?

The tiles on the walls of my bathroom, ktichen and laundry are all popping off and drummy. They need to be repaired, and given that soooo many of them are lose or already popped off I believe they need to all be removed and the place retiled. The strata manager has said the body corporate will pay for the repair of the tiling on my unit walls which are shared property with another unit or common property, but will not pay for my walls which are internal to my unit (ie back onto the bedroom or loungeroom etc). Is this correct? Apparently this is happening in alot of the units in our building, and this is how the body corporate have decided on how to address it. They are also arguing about whether to repair (ie clean up and stick back on the old lose tiles) or retile. I feel that because probably 60-70% of the tiles are drummy or already off, then retiling is prefereable as the problem will probably persist after a repair, with the rest of the tiles popping off over time. What are my rights here?

SMHC