I can buy currys e vouchers at a discount, Instead of paying with cash,
I first buy the vouchers,
then use them to buy what I want from currys
(They have discounts on vouchers for lots of different stores).
As the fan was £550 I checked currys had stock, then bought exactly £550 of vouchers and went back to currys website and bought the fan with the vouchers.
The company who sell the vouchers at a discount is called Xexec, they are a legitimate reseller of currys standard evouchers.
Because of currys terrible service they said they will swap the vouchers back for cash but can't until currys put the money back on the vouchers.
There is no problem with the vouchers. It's just currys took the money in error and are dragging their feet in returning the money they took in error from the vouchers