Irrespective of whether the seller was a private individual or a business, the goods sold to you must be 'as described'. As they're not, you have the legal right to a refund of both the purchase price and the carriage charges.
[Sale of Goods Act 1979].
If the seller is operating as a business (even if they've not actually registered with eBay as a business seller) then, even if the goods were perfect, you would have the right to return them anyway for a full refund. If the seller had met his/her legal obligation to tell you that (before you made your purchase) he/she could have required you to pay the return carriage costs. However, as (by illegally stating 'no returns') the seller has failed to do so, the vendor would also now be required to refund your carriage costs, as well as the cost of the goods, even if the goods were in perfect condition.
[Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013].
A seller with 100% feedback is likely to want to retain it, so you probably won't have any problems getting your money back.