Ebay allow you to return the item for a full refund.
What do you mean about the seller absconding?
If you want to take more action than Ebay allow (return/refund/feedback) you would have to contact Trading Standards or another official body.
However, generally nobody will take action on the word of one dissatisfied buyer.
"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)