Vodapay BP voucher ****

I have tried now 7 times to redeem my BP voucher purchased on Vodapay, on different days and at different gas stations. Every time I get excuses about the network being down or similar, as the transaction shows as "declined", needless to say quite embarrassing. I'm only notified are filling up petrol that the transaction of redeeming the voucher was declined. I kindly request a refund. While responsibility of this error is shared between Vodacom and BP, I will post to both companies.