Airtime disappearance

I am so appalled by the way you guys treat your customers. It's part of the reason why I stopped using my Vodacom Sim card for a while. So a week ago I bought airtime then converted part of it into VC-to-VC minutes so I could call a friend. I couldn't get through so I ended up forfeiting it. Understandably so considering that he called me back and the minutes were valid for the day. Now I left the airtime there since that day and yesterday I decided to check and buy minutes. To my dismay, I was left with R1 odd on the SIM card. I never used that phone since that time when I tried to make calls. I blocked all content services looooooong ago. All I want to know is what happened to my airtime and why? This is exasperating and I really don't have time to be busy holding on the phone to understand hogwash about how my airtime miraculously disappeared. Please fix it. I really don't have the energy and not really in the mood to port my number out of your reach.