I have had this happen to me before... got an e-copy of a book. I e-mailed the seller and told her that she either refund my money and removed her listing, or I would turn her in for copyright violation. She did not have the right to scan a book and send it out as a PDF. She refunded my money. I was afraid to leave negative feedback at the time because at the time, sellers could still leave negative feedback for buyers and I wanted to keep my 100% rating.
Give e-Bay time. They will probably look into it and will put her account on suspension.