I have had a order not turn up for over a month. The vendor is insisting I open a dispute for a 35% refund. From what I read and looking on dream this isn't possible. I have asked for a partial reship but he won't send again and said I need to open a dispute, what should I do?
There's no 'dispute' to be had. You FE'd. Even Dream warns you against doing this when placing an order. Even if you hadn't, since it's been so long the auto-finalization window has passed and you still wouldn't be able to file a dispute. At this point you've likely also missed-out on leaving a bad review. Money gone, vendor fucked you, and you're SOL. In the future, don't FE and don't wait so long to dispute.