This is terribly bad selling and eBay do not condone it.
The seller should cancel the order which will fully refund you. You may then contact Customer Services explain the cancellation was not requested by you, and you're very disappointed not to receive your item. They will charge the seller a seller fee and pace a damaging defect on their account.
If they do not cancel. Open a case for item not received one day after the item's last estimated date for delivery. If the seller doesn't refund in 3 days, escalate the case and eBay step in and force the refund.
Do not worry, your money is safe, if you follow the above guidelines.
Depending how this refund is managed the seller can end up paying a seller fee and gaining a defect on their account.
It doesn't take too many defects for eBay to remove the seller from their site. eBay do not like unhappy buyers, they tend not to return to their site to buy.
@xoxy_10