Missing voucher

I placed an order For flowers 3 days ago using a Netflorist voucher to the value of R500. While I was entering my card details for the balance the system crashed and the order disappeared. When I tried ordering again I could not use the voucher as it had already been redeemed before the system crashed. I have been phoning for 3 days and they keep telling me that my voucher is with their ‘missing vouchers’ department and I have to wait for them to email me. There is no way that you can speak to someone in that department. When ordering from Netflorist it is usually for an occasion and the order needs to go out on a specific day. What is the use of sending something when the occasion has already passed? I find this poor service utterly frustrating and totally unacceptable.