Hiya,
Many have started legal action...I finally started in 2010. I was told I had a bank guarantee by Lawyers of Spain (who were associated with Andalucian Dream Homes) but this proved to be false. The bank guarantee was between Interlaken and Med Lux Homes (Ocean View) so I couldn't go that direction!
I now have maria from Costaluz lawyers dealing with a multiple action. I think you should contact her....if you mention my name she'll know your determined to sort this out. Interlaken 2003 SL were incorporated by a larger company that went into insolvency/bancruptcy earlier this year ...so the bank is now responsible.
I also believe that the poor build quality etc is down to the corruption in Casares town hall. Owners can beautify the site as much as they want but the build quality is terrible.
Contact Maria after 7th of January as the practice is closed until then. Happy New Year!
Gill