Delay of reversal

On the 25th of May i went to a vodacom shop in Maponya mall to go withdraw an amount of R600 but system gave an error and they could not withdraw the money for me as I also received an sms stating that i have got insufficient founds on my account yet when I viewed my balance it showed a balance of R694 but I left the shop with out the withdrawal.On the 27th May I went back to retry withdrawing at the Maponya Branch again but it gave the same error as it did on the 25th, I then contacted the Mpesa call centre for assistance and the consultant that i spoke to told me that she will escalate the metter to the finance department because on her side of the system it does show that i had enough founds on my account (An amount of R694) was still available by that time and i was advised that everything shall be sorted within 48 hours which i did not get any feed back and got a ref number .But on the 31th of may i tried transferring the balance to another number i got a message reading that I could not transfer the amount of R600 due to my balance,right after that I viewed my statment that showed that my balance is now R87 and that R600 was withdrawn on the 25th with out my acknowledge.