Qualcuno può aiutarmi a capire?

your Nebenkosten are 1335,56€ for the 200 days you stayed there last year. some deductions were made and the Grundsteuer was added onto it. you paid 6,5* 200€ Nebenkosten for last year which is 1300€.

your entire nebenkosten were 1505,71€ so you still owe them 205,71€.

the other pages show you the detailed costs for heating and such so that you can check if they’re correct