You don't need to speak to eBay, and if messages are not sending, they can be glitchy, then if you are still within 30 days of the item's last estimated date for delivery just proceed this way, as you are guaranteed a full refund, under eBay's 30 day MBG, Money Back Guarantee policy.
You have received an item not as described, go right of the item in your Purchase History and from More Actions select... Return this item selecting the reason Item Does Not Match Description.
The seller needs to accept this case within 3 days and refund, if they want their item back first , they need to pay for that fully tracked return postage, then on receipt of their item they have 48 hours to refund you. If they don't , need to escalate the case, ask eBay to step in, and they'll force the refund.
Never listen to any excuse or promise from the seller to close the case early, and do not forget to escalate.
If 30 days have lapse, try your payment provider now for help with a refund.
@sanh80-0