no refund

I booked a return ticket on Sunday the 30 June, I later changed my mind and decided to use my car, I called them to cancel my ticket and do a refund, but for some reason their is no customer service on Sunday, so I emailed them and even went as far in my email to say they can only refund the second part of the trip and kept the payment for the first part, I have not receive any reply for them so I called them on the 2nd July, after trying for hours to get a hold of someone, I got through to someone, the lady said she has not recieve any email, I told her I have proof of the email and even the call records that I tried getting through to you, she said she will come back to me, after the lady no reply from them on the 05 July i Called, again and the guy said he will speak to his supervisor because he only found the email on that day (my trip was to return for the Friday), so he will call me during the day, On Monday 08 July i called again because no one got back to me, i spoke to lady and she told me I will not get a refund because the ticket wasn't cancel and I never inform them. I ask to speak to the manager, she then said manager was not in the office, she took my number and give me the manager Dikeledi email address, I send all my emails to Dikeledi, I have still today not recieve any calls or any reply to my mails