Have you already opened a case? If you haven't, follow the instructions from @*vyolla*
Business sellers have to accept returns.
If you have opened a case and the seller refused to accept a return, did you use the reason that the items were the wrong size or didn't fit?
A private seller would be able to refuse a return if you chose that reason.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)