Service Provider

On the 09/12/2017 I recharged my account with R12 airtime to make a call,after recharging my balance was R12 I tried to make the call but,the number I was trying to call was not being answered therefore my balance should still be R12. On the 10/12/2017 I try to buy a voda to voda bundle for R5 and it tells me I have insufficient airtime yet I had made no successful fone calls between the 9th and 10th after recharging with R12 anyway, I checked my balance and I've only got R4.44 so I recharge with another R12 which puts my balance at R16.44. I then purchase a R2 voda to voda bundle for 10minutes so I make my Vodacom call only to find that all this time I was under the impression I was using the bundle I had just purchased I actually wasn't it was instead eating in to my airtime after the R2 for the bundle was debited... This is not the first time this is happening to me Vodacom needs to look in to this as I am not the only one experiencing this problem where airtime just disappears...