Finance Dep. is not working and Costumer Service is RUDE

I have been trying to get a Credit Memo for 2 different reservations nearly for 2 months (the amount is nearly 2000 Euro). Even though the costumer service has approved our request and sent the information to Finance, our money still kept captive on booking.com. I keep sending messages and they sending automated non sence replies for a long time. 

When you call the finance, there is no one picking up and your call directed to costumer service. The costumer service is one of the bad service i have encountered for a long time. For a multimillion dollar company i would expect much better. I expaine the situation to lady and the answer i got was "if it is a big problem for you stop working with booking.com" can you beleive this attitude ? Booking.com litterally forcing us to pay an amount we should not pay and that is the answer we are receiving.

When they need someting from the hotel we are receiving 10 different emails, phone calls and deadlines, IF you expect the same service, you people have to treat your partners the same way !