I went for the Brewdog advent calendar deal yesterday. Bought a 25 quid voucher having never used Wowcher before.
The voucher doesn't work. Wowcher do not respond in any of their customer support channels. Their WhatsApp bot tells me to contact Brewdog who tell me to ask Wowcher for a refund that will take weeks.
Seems like a case of 'if it looks too good to be true then...'