Hi, Maddy,
Turned myself into Marple for this one.
I have discovered with help from our Manzana Presidente and contributors to the EOS General Forum that the debit is for water, Acosol using a different trading name/reference - Mancomunidad de Municipios de la Costa del Sol Occidental.
Googled for the website, clicked on the "Water" tab and Acosol appeared on the screen.
Not sure what your larger debit is for but the amount sounds to me like it could be a full year's IBI in one go.
My earlier electricity mystery was solved by our tenants who rang Endesa. A few previous readings had been estimated only, so this one was a catch-up.