Booking.com hasn't paid since January

I'm Polish and I have an apartment in Spain. I have set up payments from customers through booking.com. For six months I have been waiting for booking.com to pay me for a booking that took place in December 2019. There are two payments associated with it, one for the booking itself, the other for the refund of the commission (credit note issued in February). I wrote messages on the extranet several times, I also called the CS in Spain. On the extranet there is no answer, CS in Spain claims to have sent a request to the financial department in Spain. I also contacted the Polish branch to get help, unfortunately it did not work. I was promised twice that the Spanish financial department would contact me, but nobody calls or writes. I can't reach them, the Spanish financial department doesn't answer the phone. This is an outrage!