Toys R Us voucher wrongfully redeemed

Hi there,

I took out a voucher advance for Toys R Us. I attempted a purchase on the Toys R Us online platform. The order total including delivery was R384.80, I app**** the R300 voucher and I had to pay the outstanding balance of R84.80, the payment expired due to the OTP taking too long to come through. I attempted to make the purchase again using the same voucher but this time I am receiving an error message “please enter a valid gift card code”. How was the voucher redeemed when my payment was unsuccessful? Voucher number is 6824******74

I tried to reach out to toys r us but they say I must speak to Vodacom. Please can someone assist me, I cant be paying for something I did not use. I'm at a 2 day work conference, if you can kindly contact me in writing please.