I am no apologist for spanish controlers, far from it, however it has to be said that Spanish is an ICAO aproved language and as such both pilots and controlers are perfectly entitled to use it. You may not like it but that is the way it is, you can lobby to have the rules changed. The rules are that if either party changes to english the other must also respond in english.
The language issue, that has been debated here soooo many times, I think is quite separate from poor discipline.