Thanks guys for the suggestions.
I have just writtten to my friend and suggested that she sends the following email, to see what response it has.
From what you say GC Resorts were in breach of EU law, thus they have committed an offence, or offences, contrary to the criminal law of Spain.
As you are fully aware of the circumstances, under Spanish law, you can make a Denuncia on behalf of any, or all those affected (even initially on line or on 902 102 112).
We do not need to do it individually nor in person, and you do not need any kind of ‘authority’ from us, written or otherwise..
Should an investigation be mounted, then any additional information, which the Guardia Civil should need, can be obtained though the services provided for just such matters through INTERPOL.
Please confirm what action you have taken and the relevant Numero referencia de la Denuncia