Suggest you redact out your address on that screenshot ;)
Those items are not for sale anymore. They were only available for that particular week.
Yes they stay in your cart until you remove them, but you can't purchase them outside the week they were on sale.
I received the same email you did from a purchase I made earlier this week. Seems xsolla is having a lot of issues this week
Thank you guys.
I've placed this information into an email to that support address. I think I'll remove this post as it is more public than I care to share. I'm not much of a facebook fan either actually :)