Vodacom recharge vouchers bought from P&P don't work

On 28 August, 2019, my mother (a pensioner) bought three Vodacom recharge vouchers from Pick n Pay. Only one of the Vouchers actually worked. I believe this to be a Vodacom problem, but I think it's important for P&P managers to also be aware of the fact that there is a problem with the vouchers they're issuing, and to investigate the matter (to see where exactly the problem lies) and to bring it to Vodacom's attention, before it damages P&Ps reputation.