How I understand that part about not giving support.
They are not giving support to customers but they should still provide upcoming updates for the theme - if on some point theme is broken (does not work with some new version of WP) and some of the buyers report this to Envato - they can disable/remove this item from the market.
Of course, they can remove it itself at any time if they will not update any more the theme.
But, in your case, theme was sold with included support, and now it is not any more, and I think you have a full right to ask for refund (if that is an option for you).
That is how I see this situation, maybe some of Envato members will provide us more info about this.