Disappointing Service From Host

I am writing regarding my recent stay in an apartment in Nerja booked through Booking.com under the name Louise K***, reservation number 5981250177, with check‑in on 12 July and check‑out on 16 July. We booked this particular apartment from Ireland specifically because it advertised air conditioning, as we are not used to high temperatures and this was a key requirement for us. On the second day of our stay, the air conditioning stopped working completely. I immediately contacted the host, who informed us that an engineer would come. We waited the whole day, but nobody arrived. I contacted the host again and my message was ignored. When I clearly expressed how disappointed we were, the only reply I eventually received was “sorry”, with no real attempt to resolve the issue. Because the air conditioning was never repaired, we were unable to sleep properly for the last two nights of our holiday due to the extreme heat, and this significantly affected and, in our view, ruined our stay, even though we really fell in love with Nerja itself. We feel that if the host had been more considerate and arranged an engineer promptly, the issue could have been resolved quickly. In light of the lack of a key advertised facility and the poor response from the host, I am kindly requesting a partial refund or appropriate compensation for the days during which the air conditioning was not working.