School not able to book exam for Oct Series - claiming Cambridge changed the process and its broken

I had given a list of exams to school to book 2 months back, first they said that last date is 15 Aug, don't worry and we will book in time. Now I have been following for 10 days already and now they are saying that Cambridge changed the booking process and introduced some authentication etc and we are not able to book. They claim that they have escalated to Cambridge and they are working on it, I mean that there are only 3-4 days left ! Does it look like a plausible reason, anyone else faced this problem?