We had to call the Hydragua office yesterday after a similar problem in one of our villas. They were very helpful, said all bills were up to date and there was no known cause, but advised we call the Local Fault Office on 900 101 270. Within 15 mins an engineer had been and water was restored.
Seems they had been doing some work in the area and had turned off a section of C/Luxemburgo and forgotten to turn it back on!