I got the reply from sixt to my complaint letter. really funny. they are suggesting that I book ECMN to IWMR because than the probability is higher that I get an upgrade with my platinum card. And appearantly the platinum prices are much lower for weekends than internet and private customer rates.

however, they defend their price increase and stick to it. even though they didnt really. They wanted to increase prices by a further 50% on 1st april. Then they postponed to 1st june and now they scrapped the 2nd increase completely.
so maybe if more of you write complains it will help further.

Even though this is not the right thread here: anybody suggestions for CDP/ID at europcar and hertz if we all decide to change?