I think you will get your money back after a bit of a fight . I think you would have to take them to court and you will need a spanish lawyer ( court and lawyer fees ) dont know if you will have to pay the fees it may not be like it is over here were if you win they pay !! dont know
Also if you do this you will lose out on how much it as gone up over the years and they will be able to sell it for more money to someone else when it is finally finished
when i went over to spain in 2003 looking for properties there was someone there that said they was waiting a year and half longer they said the spanish are very slow just hoping it will be done in time for summer 2007 , we have waited so long i think it's worth hanging on to.
In our contract they do have up to January 2007 so really they are only a bit behind if it's done for say June thats only 5 months behind which i suppose is ok after what that woman told me back in 2003 and we may even get compensated ya never know
HOPE THIS NEWS AS CHEERED YOU UP A BIT