I quite agree with you that its about time to get these things under control.
I have the same situation in the area where I work. The council actively look for a piles of sand, bricks and skips outside a property and query what the owner is doing. In many cases they have been to properties and told the owners that, for example, they dont have a building licence for a pool or a wall extention.
The planing authority in my area is also Elche, the same as Catral!
How these builders managed to build there and not get noticed is a mystery to me.