Renovation of Balcony

HI We are a small three unit self managed strata and we have an issue I would like some direction on. Two of the three lots have second floor balconies off the main bedroom, one of the lots removed this balcony many years ago for an extension on the ground floor. As a result there is an agreement ( Verbal only) not in by laws that the other two lots are responsible for maintaining their balcony.

We have been in communication with one of the  lots as their  balcony is in very bad condition and the owner of the lot will not respond to e-mails requesting that they have the balcony fixed and. I have  sent many emails and texts and have an e-mail trail of the communications between the Strata and the owner, but I am wondering where we stand in having the Balcony repaired. Can we force the lot owner to repair the balcony, Can the Body corp have the balcony repaired and charge the Lot owner for the repairs ( I have a feeling the money will never be returned as they are also behind in the strata payments)

I have managed lately to have an inspection of the balcony completed and I have been advised that if left any longer it could have major structural damage to the unit and need major repairs