Horrible service from call representatives

Once again and without fail, Booking.com representatives are probably the worst customer oriented people I have come across. I waited on call for 30 mins and once I told a Sumaya that I don't want to be disappointed again by their poor service and unresolved concerns, she simply hung up. I don't want to call Booking.com. I want a contact email where I can write my complaints to, but you will never get that. I wonder if these firewalls have not been deliberately built in to protect the guilty. Disgraceful service.