Flat deposit return - dispute with agent & expert = options?

Hello,

I left my flat some months ago and have been in long discussions with the estate agent and expert regarding my guarantee deposit.

Basically, we disagree on a number of things.

What steps are there for independent arbitration? Or similar.

If a "justice de paix" route is pursued, what are typically the costs and timeframe involved?

For some of them I had the items already added to my entry report + photographic photos. But the estate agent decided that the entry expert agreement (in writing) with my amendments are not valid as she felt the expert did not agree with the amendments (from the wording of his acknowledgment to accept them..). Some of the items were already paid by the previous tenant (not repaired) so the agent is looking to repeat the same magic of money for nothing.

For some others, the repair was already agreed with the estate agent and landlord (at their costs) before leaving (email in writing). But the position of the agent is that the comparison can only be made at entry and exit therefore anything in between is not accepted. If the repairs were completed before I left then it would have been fine...the repairs were the responsibility of the estate agent. This fails my logic test here...then again one person's logic is not the same as others.

Out of principle, I am not in favor of paying for the wrong reasons.

My Belgian colleague calls it the "expat tax" that some people/companies will unfortunately seek to take advantage.