Birthday voucher

My child received a birthday voucher from old mutual to use at [URL Removed] she tried to use it on the site in gave a message thats she should insert a voucher number wich is not on the voucher she received. I phoned the old mutual call centre and indicated to me they will not be able to assist me but gave me a email address where i should send an email and get assistance. Up to date i have not heard or received back an email regarding this issue. So she can't use the voucher she recieved and it expires 3months from the date of Birthday.