Ebay can only step in and escalate if you have opened a return.
Have you opened a return case through Ebay or have you arranged this through messaging the seller?
If you have an open case, go back to the case. The option to ask Ebay to step in should be there by now.
If you have not opened a case through Ebay, do it today.
"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)