It is unfortunate that you use terms below in bold in you original [post because this is serious and growing problem and there is lots of good advice on this forum whichi beleve explains things well
there seems to be a lot of confusion and misinformation with regard to many aspects of the completion process being posted on here lately,
there also seems to be a lot of panic,
Our advice is based on 4 years of practical experience of working in Spain advising people with these problems and we know of at least 5 other developments where the builder has disapeared leaving owners high and very dry
The fact that some banks will allow mortgage only makes the issue worse as what normally happens is that a bank will loan on the development on the basis thay they are the preferred mortgage provider and may not be quite as dileigent as another
The lawyer may have been recomended by the agent so again there may be another commercial interest
Finally with all of the most recent arrests at Town Halls and even some properties being originally legal ,and then not legal it pays to be extra cautious