No service whatsoever/can’t get hold of them/they don’t call you back

Since 11am I’ve been trying to change my flight tomorrow. For some reason it won’t allow me to change it online, so I called their customer care line just be on hold for a while, so I requested a call back. It’s now 6:20pm and still have had a call back. I called them again at 5:30pm as they work until 7pm. I’ve gone from being number 10 in the queue to number 7 over 11min then remained number 7 after 25min, then number 5 after 40min. I decided to end the call after 40min and requested a call back once again. I’ve paid roughly R2300 for my flight and I refuse to throw that money down the drain. I demand FlySafair to FINALLY assist me into changing my flight or to give me a voucher. My flight is still booked for 8am tomorrow as after many attempts I could not get assistance from FlySafair to change my booking. Please contact me urgently!!!