Every Spanish business has a complaints book available, so don't hesitate to use it if you need to
Spain's consumer protection laws are fully in line with those of the European Community. The local provisions are at municipal level.
If you have an issue that you are unable to solve directly with the business, the first option you have is the complaints book. Every Spanish business has to offer a 'Libro de hojas de quejas y reclamaciones' in which you can enter your complaint, which is an official record, inspected by the municipal consumer office. Requesting this is usually enough to initiate a solution to your grievance!
Failing or further to that, you can seek advice and make a formal complaint at the municipal consumer rights office between 0930 and 1330 hours, Paso Antonio Machado 12, Malaga. 951 92 60 57 More info here.