Refund from Avo SuperShop

I bought 3 blu vouchers on Avo and paid it from my vodapy wallet. They took the money but the codes was never generAted. So they ssis i will be refunded in 7 working days it has been 8 days already and nothing yet. Now the agent id telling me i must get a written certificate feom vodacom to say the money was not received. Vodapay does not have statements yet. They are refusing to refund and every agent sends you the same message. No one is doing anything. AVO IS THE WORST EVER