If you feel you have a complaint that should be resolved, then you lodge a complaint with the telco, if you feel they haven't resolved your enquiry then the TIO can assist with reviewing it further for you. If they feel that compensation is appropriate then they have the right to enforce or recommend it.
They are meant to mediate the situation and find a suitable resolution, if they agree that the telco have offered a suitable resolution and you have declined it then they can uphold that, increase it or reduce it, it really can go any way.