Wrong voucher

<p>Hy. I work at Soshanguve Spar Block FF as a Cashier.On the 5th of July 2017 at 08:58:26 a customer purchased R100 unipin voucher,after a while when the customer left we realised we did a mistake.we are trying to contact unipin to retrieve the voucher as Blue Label can no longer be able to cancel the vouche as the customer has already redeemed the voucher and only unipin can retrieve. Please kindly assist. The meter number of the person who used the is ********** 8026 but we cannot trace the customer address.</p>