A landlord is entitled to ask for service costs, but there are juridical requirements. The landlord can only charge service costs for incurred cost, usually this consists of cost for utilities (Gas/Water/Light), movable property (furniture/microwave/washingmachine) and can also consist of internet/tv-connection, cleaning, certain types of insurence. If the landlord also takes care of small daily repairs, he is also allowed to charge you in the form of service costs.
Note: During the year utilitie costs are usually paid in advance. At the end of the year a balance sheet is being made. Defiations between the deposts that was paid in advance and the amount to be paid can occur. If your deposit was higher you will retrieve the difference, if your deposit was lower you will have to pay the difference.
When you disagree with the used amounts you can start a procedure with the rental commission.