I have paid my last invoice to the old Booking.com bank account

Booking.com has recently changed their bank account.

I always pay my invoices on time but due to the bank change I didn't noticed and paid the way I usually do, on line, on time.

One day next after invoice was due, I got a reminder it was overdue. 

Contacted booking.com and forward my on-line banking statement. This was done on three separate occasions, via extranet, phone call and messages. All of them ignored/not answered.

Today I received a message my account has been suspended.

Called ‭+44 20 3684 7923‬ and pressed option 3 (invoices and payments) and the person that answer was from reservations, not finance. I have asked to speak to finance and was informed there is no way to speak to finance departments. 

Any advice on how to speak to them?

Thanks,