Wrong Billing

I loaded the R30 airtime and it was disappeared when I was trying to make a phonecall , when I phoned the Call centre I spoke to different consultants that are called professionals but some of them are veeery rude .<br> <br> I was not fighting with MTN but was only asking for clarity of where my airtime has gone to ,but no one seemed to know and some were dropping the phone to my ear.