You should contact your Strata Manager who can inform you whether the garage door is Strata or Individual Owner responsibility.
If the garage door forms part of the common property and is the responsibility of the Owners Corporation, you should notify the Strata Manager in writing of the time, date and detail of the incident so that the appropriate course of action can be taken. This may include the lodging of an insurance claim for accidental damage. Please be aware that should the garage door be the responsibility of the owner, this may result in the person responsible having to pay for all costs of the repair.