electricity charges

we live on a mobile home site i Girona, we had electricity meters installed about 10 months ago, the rate originally was 0.18c per kw, it has now risen to 0.30c per kw, when i enquired why we have had such an increase is was informed it was calculated thus............ when he recieves the bill he adds 30% on top of the rate he pays, this im informed is to cover the installation and maintenace costs, we pay a ground rent each year and it was my understanding that this was to cover such costs.

my question is ......... is it legal to make a profit on the charges he recieves and is there a limit to the % increase that can be applied ?