do nothing. ignore him/her and move on.
send him one final e-mail stating all the offers you have made. tell him this is his last chance and he needs to contact you infroming him which option he would like to take. also in this e-mail feel free to point out some of his statements, e.g. you have stated that you did not read the full description of the product, which stated the exact condition that i have sent it to you therefore i feel no obligation to refund your money or to make you any offers in regards to exchange however i have decided to put forth to you once and for all the offers that i have previously mentioned and if you choose not to respond within 24 hours i will consider the matter dropped and will no longer respond to your e-mails. if you clearly stated the correct condition of the movie then you are not to blame and he should not be entitled to any form or re-fund.inform him that the manner in which he has been contacting you is harassment and if he does not cease to contact you in a rude or impolite manner then you will take his e-mails to your local authority as you fully described the contidion of the item and you have done no wrong so you will be making a harassment complaint.