Horrific service and bad billing method

This is the second time this has happened and nothing was resolved despite customer service looking into it. I purchased 6mins for R2 now and used yellobucks. Yellobucks were deducted but not airtime has been sent I called the call centre and the agent was not very good in understanding the issue or resolving. She didn’t even want to spell her name but I think it was LULEK. She eventually said she is escalating and must wait 2 to 24hrs. This is unacceptable I am billed and no minutes are provided and now I must wait.