There is no point in talking to eBay. Their time limit for claiming a refund for any reason is 30 days. You could possibly try your credit or debit card company, if that's how you paid, but it's doubtful whether they will be able to help for a year-old purchase.
If you bought it from a business seller they should still take some responsibility, you could consult citizens advice or a solicitor if they won't. If you bough to from a private seller any rights you have are probably only theoretical.
It's up to the school to report the item as stolen. The police can contact eBay in any investigation, but this is unlikely to help in getting your money back.
Good luck anyway - but do please remember that eBay even warns buyers in the user agreement that "they do not guarantee the existence, quality, safety or legality of items advertised, or the truth or accuracy of descriptions". Buying on eBay isn't like buying from the shops. eBay is a jungle.
