Sorry to hear your problems with Fadesa. The only way to deal with Fadesa is not to deal with them. This of course does not help. Whilst I do not wish evil to any one. Fadesa, crisis is good news to future buyers as they the buyers will be protected from the Fadesa business practises. I am also certain that Fadesa as we them in future will not exist and they will be fully retrenched doing local developments in Spain or in Eastern Europe. As you probably know, that Fadess has been sold in Morocco.
Before you take a decision as to how to approach your problem with Fadesa, check out
The Unofficial Alkudia Smir Forum. There is a guy there called Shak, check out his posting & you will know who you are dealing with and how to approach this issue. He has been picked on by the forum users who were mainly agents to protect their commissions.