I don't think I signed up for this & I can't find where to cancel!

A few years ago, I bought the "Voices From The Underground." However, it has moved to this new platform. Unfortunately, I cannot access. I tried to use the voucher, but it says that it is invalid or has already been used. Could someone please help me?

I purchased Fantastic Fungi on Louie's last website but I'm not seeing a link on this new site to be able to watch it???