You listed the skis with a postage price, stating that Parcelforce was the courier so the buyer's expectation is reasonable.
If you can't find a delivery service to accept and deliver the skis, then you will have to cancel the sale and relist the skis as collection only.
The disappointed buyer could still leave you negative feedback.
I am not sure what you would want Ebay Customer Services to do.
"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)