The Spanish company that is owned by the Kingfisher Group, the same company that owns B&Q is called Bricodepot and the nearest brannch is in a place called Crevilente, close to Alicante airport about 1 hour drive form Corvera
B&Q as a brand do not exist in Spain
Their website is www.bricodepot.es
I visit this place a lot and unlike B&Q, and because of the difficult employment situation in Spain they emply very young staff and you would need to speak Spanish and there is an area on the website where you can apply and send a CV
http://bricodepot.infoempleo.com/default.asp?pagina=cv&id_origen=28