Water Leak - Undetected

We received a letter from Acciona in June to say that our water consumption was higher than normal.  When we received our bill this month (July) it was 100 euros more than for same quarter last year.  We checked the meter after turning off all water supply in the house and it is still going round.  We contacted Acciona who will not come out to check.  We have no idea where the leak is - presumably underground somewhere and have heard that to get someone just to check with some apparatus is expensive. We would then have to pay a plumber/builder to dig up paving/tiles repair leak and replace.  Does anyone know if there is a cheaper option? ie a plumber/builder that has the equipment and can do a complete job.  We are close to Pilar de la Horadada, Alicante region.  No doubt the next bill will be even higher if the leak is becoming greater.

HI, are you in a community?

Hi Goldie

No we are not in a community.