Same happened to me. Hey said they couldn’t track the purchase for some reason and that was the end of it. Bit disappointing.
Mine still hasn't tracked. Sent an email to VoucherCodes with proof of purchase.
They paid me the voucher last week. 20£ amazon voucher for 74p spent on viator :)))
Thank you I got my voucher yesterday My boyfriend too 😁😁😁
Got mine to! :) thanks a lot