Disgusting service that dont want to refund my money

On the 30 March I booked a bus with Delta for 13:20, from Capetown to Pretoria. I waited over and hour until i went to their office for them to tell me the bus will delay and will arrive @18:00. I booked another bus because i had an emergency I was rushing too. I called delta and they told me I must wait for 18:00 as there s nothing they can do. I have emailed Delta for my refund since I never travelled with them. They told me they issuing me with a voucher I can use to travel again. I want my money this people are ****s they never answer their cell phone customer service number they even drop the call the moment you go through. I have called Delta and sent several emails all i want is my refund. Why give me a voucher when the bus was late on your side? Delta coaches please pay me my money i want nothing else but my money. I will not stop until u pay me my money. Delta you are a ****, unproffesional, rude customer services lack of everything i want my money.