Terrible service

Called in because my voucher was invalid but I hadn't used it as yet, the first person I spoke to was helpful and said airtime was loaded on my phone but after the call when I checked it wasn't done. Called again and spoke to Yanga Mvutuza and he was very rude and then asked to speak to a supervisor before he put me on hold he asked someone if they were going to take the call and whoever said no I was then put on hold for more than 12 minutes. He said they were all busy and I can go ahead and do whatever I want to and I must take it further. That's bad customer service this agent needs to go for customer service training...