Eredeti szöveg - Francia - J'aimerais savoir le prix d'un mètre cube d'eau. ...

Hello experts

I would like to translate this into Dutch.
I understand it all apart from one word - is 'décompté' 'specified' or 'deducted'? I can't seem to find a satisfactory answer on the internet...
Thanks!

My bridge (just to make sure I do understnad the rest):

I would like to know the price of a cubic metre of water, because according to my calculations the result is not the same. (i.e. the invoice he has received contains the wrong total price, he thinks)

I would also like to know the details of the 20 euros of monthly charges because part of this is for the water; but that has not been detailed or deducted on the invoice.

Best regards

CC: Francky5591 Bilge Ertan gamine

deducted

Thanks