Misleading and horrible customer service!

Very unhappy with mango airlines. Had a flight from jhb to durban on Friday at 14:45. We got a phone call from mango on Wednesday saying that the flight was cancelled and they had to put us on either a flight that Friday morning or otherwise on Thursday evening. Both of us had previous work commitments ( the one passenger is a surgeon that had to be in theater for surgery). So we told the consultant we cant do any of those flights and would like a refund. She started laughing and said they cant do refund and our only choice was to move our flight time. We had to cancel work commitments and finally chose the 11:30 flight on Friday. However my biggest complaint is that when we got to the airport on Friday we realized that our flight was not really cancelled, they just changed to a smaller aircraft and some of the passengers did not fit..so we were never even given the option of staying on our flight by mango, had to cancel work commitments and have a loss of income etc without being told the truth or giving us a option to stay on our flight! Misleading and horrible customer service!