Call issues

Hi, For the last few months, I could not contact booking.com with any mobile phone : the bip option doesn't wok (press 1 or 2 ou 3...). I Tried with an Iphone or a Samsung but that did not change anything. I tried with my landline phone to do that and it worked but not since today... when a dial the number, I dont have the answering machine, just a busy dial... I tried with 0064 XXXX, it works but when booking.com pick up the phone, I can not hear anything. Could you please explain what happen because we have no option to contact booking.com quickly.

I sent this message on my extranet but do not have a reply for the last couple months... Thanks