Where can I find a large electrical store

Look online (Amazon.es. MediaMarkt etc) or if you have to see it before you buy it try El Corte Ingles on the smaller Euronics stores. It does depend what you are looking for.

Hola    Tine 21    in Roldan     take the  RM19   from San Javier   towards  Murcia       come off    the  Roldan / Balsicas  exit      at the roundabout  

3rd exit   towards  Roldan           as you enter the Town     Tine 21 is on your   right      (set back a bit)

they sell    fridges   freezers   cookers  lights   kettles   so on     with some  kitchen "stuff"   and  some furniture  over two floors  

even fit lights   and install      

Found euronics on main road LA delivered oven ,installed,took old one away

Brilliant service and spoke English(bonus)

Milar

Calle Dr. Pardo López, 13, 30730 San Javier, Murcia, Spain
Are small shop  but they have range for everything.  Reasonably priced  and can sometimes do same day delivery