As kopenhagen said, avoid mentioning any sort of dispute. Try getting your point across without using terminology that is automatic grounds for removal.

Under the Leaving feedback for sellers help page, keep in mind that "If you decide to leave negative Feedback, make sure it's fair, factual, and relates specifically to your transaction with the seller. Remember, Feedback is about your experience with the seller – it's not a review of the product you bought."

eBay also state: "If a member has violated one of our Feedback policies, you can ask us to have it removed. Once we review it, we may remove the entire Feedback, or just the comment or the rating."

Hence, if you had to open a dispute in order to receive a refund, you can say something like, "Refunded - item not as described. Seller failed to resolve issue personally."