I have tried, lots of times, to use Spanish Yellow Pages and Directory Enquiries. Usually without success.
One of the problems is that Spanish phone books are divided geographically but not always consistently. For instance our phone number is listed in Pinoso but that for our next door neighbours is listed in Culebrón - maybe the ten metres makes a difference! And both our listings are incorrect anyway. One reason is because the English and Spanish forename and surname systems are different. As Christopher John Thompson I am listed as Sr. Jhon (sic).
Another problem is that lots of people simply aren't listed at all. They just aren't there.
Yellow Pages seems to be based on the ordinary phone book so it has the same general structure. If you want a plumber then you look under the section for plumbers. Next you have to look under each town or village as well. In Culebrón the local town is Pinoso but if there's not a listing there you have to start going through the nearest towns, Sax, Salinas, Novelda, Monóvar, La Romana, Alguena, Elda, Petrer etc. So it's a lot of flicking back and forth as you search for that elusive plumber.
The operators at Directory Enquiries don't necessarily live near us. For all I know the call centres are based in Peru or Ecuador - all they have to go on is a database. So, if you ring asking for a plumber in Pinoso and there's nobody listed for Pinoso (remember lots of people aren't) then they too start asking for nearby towns. It can be very wearing.
The online version is better in that it trawls wider so having asked for a plumber in Pinoso it lists almost all the plumbers it can find anywhere. The trouble there is that the numbers are often simply wrong. When I was looking for a solicitor (ages ago) I rang the first six numbers. Four of them were private houses and two were unobtainable. I gave up.
I just checked, there are no plumbers listed for Pinoso in Yellow Pages. I know of three firms personally. That's why the only reliable way to phone someone is to know their number and that's why we collect business cards.