IDP IELTS — speaking slot reschedule

Myself and my wife, we booked for dec 14th general ielts test at madurai. We did not receive speaking slot on the same day which they said they will announce only 2 days prior. I was on official trip to usa until dec 13th and i have been continuously contacting them (Right from december first week onwards) either thru live chat or through tickets to get a speaking slot post dec 13th, but they gave it on dec 11th. Post that also, we contacted many times (Incident raised with flight details) but we received an email on dec 12th stating due to unavailability of examiners cannot reschedule the speaking slot and also they stated "hope you have attended the speaking slot". I really don't understand how such a statement where how can i all of a sudden travel and come for dec 11th from usa and attend. They are so lethargic with the reply. If they are rejecting or accepting they should have emailed before december 11th which is what is expected from a true trustworthy institution. Please don't make ielts as a money making scam. We regret choosing ielts idp.