URGENT HELP

Hi, i am having a problem shutting down my property, i used to hire a 3rd party channel manager Home Rent but we i decided not to pay them or use them anymore as they were really not responsive and not helpful at all. They have control over the booking.com extranet, but it is under my email, contact number and bank details. They seem to have shut me out as i can't log in to the extranet using that anymore, and when i use my email to login, the property does not show up in my account. Now there are sudden bookings coming in and it is really bad for those who come here and do not have a place to stay.