EBAY rip-offs ? Have U experienced this scandalous type of episode ?

I purchased 5 items from one seller, 4 items arrived nicely but the 5th item that cost over $ 100 bucks never arrived to me and seller wont respond to me for 6 weeks ! What am I able to do ? Pay Pal has it listed as sent cause she put it in package as article arriving but it NEVER. woe is me