Voucher Advance

On the 20th April I took a voucher advance of R100 on the Vodafone app. Paid it back 4th of May. Til today Vodacom is still trying to debit my account of this R100 I called customer care and asked if they could allocate this payment to my profile and i was advised they could not. The person i spoke to is Percy and he assured me that it does reflect as settled but it just needs time to clear on the system. How long does this take to clear ???? We are going into the new month now and Vodacom is still trying to debit my account, I had to move my money into a different account because I'm sure if they can't even allocate this payment, a refund will be even more of a hassle. I want this sorted out ASAP as I pay fees everytime that it's declined!!