Terrible service and platform to use.

I purchased a voucher from discovery and tried to use it yesterday and the payment was unsuccessfull. I tried to place the order again and keep getting an error. "This coupon can only be used upto 1 times by the same customer" I used my wife's account to check the item I want and get an error message saying "This coupon is canceled" I wanted the item for next week and the item showed express delivery and now I'm having such a big issue to use the voucher I purchased. The voucher isn't used. What do I do now? I logged a query with Zando but it's taking too long for a response. This is terrible service. Order no.