Vodapay ****med me off Vouchers, selling me invalid Vouchers.

Vodapay ****med me Vouchers, I'm never using Vodapay again after this. They clearly don't deliver. I bought 2 Debonairs Vouchers last night and tried to use them online but the voucher didn't go through and I tried it again and got an error that the voucher is not valid. when I contact them they say the vouchers are used online by my number, but I've not used them they didn't go through and also have proof of my Debonairs order history that I don't have any orders placed yesterday from the Debonairs site. I also asked them to tell me what the order number is that used the voucher they refuse to tell me. Obviously if a voucher is used then it will show on which order number. I've decided I'm leaving Vodacom for Good. They are not good.