Liability for medical costs

We visited from Australia in January last, my wife fell while crossing the street level car park of Ala Moana mall. She suffered a broken humerus - ball and shaft - she has on going treatment and pain. We contacted the centre presenting the facts in order to gain reimbursement for medical costs. We do not wish to litigate for any large sum. I have fully read the liability laws covering Hawaii and understand the 50/50 ruling. Whilst we don't deny some fault lies with my wife, she turned to see where our girls were, looking into the bright sunlight, then back into the darker car park becoming momentarily disorientated. The insurers claim the mall only covers medical claims where they are fully at fault, not because someone in in part responsible and are on their property! In my original cont