Horrible to work with Booking.com

I have a property listed with booking.com. A guest paid into their virtual card system. Booking.com now has to pay the establishment. It's been weeks and email after email and phone call after phone call. You get nowhere further than a agent at the call center who tries in very smart terms that you must just wait. I have send all banking details and info they need. Yesterday a rude person at the call center just told me that what I say doesn't matter and didn't give me chance to talk. This is not the first issue with them. Be warned, they might be good for guests to use, but you as an Establishment means nothing.