We're in a similar (though not so extreme situation). When we bought our appt, the monthly charges were quoted at 380.- per month, but we hear now they are going to be 490.-. When the appts were built and the 1st owners moved in 3 years ago, their charges were 280.-. We have actually requested an extraordinary meeting with the Gerancier (Verwaltung) to discuss this and other issues (security, maintenance etc) for next week.

You realise you are quite entitled to change your Verwaltung, if you believe they are not doing a fair and reasonable job, don't you?

About your charges, you should receive a yearly breakdown, including justifications for any increases.