Vodacom poor system and billing

I am a vodacom customer who is very unsatisfied by Vodacoms payment and invoice system.I have received a vodacom statement stated that I was in arrear. On the first of June I rectified it by doing 2 cashhpayments first at the Colonade branch and the second cash payment at The Grove branch Lynwood.The call centre which was at that stage very helpfull and my phone was unlocked.So all the payments reflected on their system.11 June I have received a statement from Vodacom per email and it reflected that I was actually now in credit.On 12 June my phone got barred again.I visited the Grove branch again with a copy of my statement,to find out that my cash payments does not reflect on their system and I have to go to the Colonade branch and try to get my receipt for the proof of payment and then take it from there to see if I can get my phone open again. Apparently it is a system problem that caused the problem which I think is unacceptable for a Institution like Vodacom and now I have to go to all the hassle to get my problem solved because of their systems and like I have mentioned it was captured the day I did the payments and secondly it reflects on my invoice.