It's automatic and just an annoyance. Happens when your purchase should have arrived and you haven't responded with feedback.
Feedback is completely voluntary and you can leave it at any time up to 60 days.
Having said that, your seller's ability to list and sell on eBay is in part controlled by his feedback and the more important Detailed Seller Ratings. Any DSR lower than a 5 will make it more difficult and expensive to sell here.
BUT
Did you notice that 'should have arrived'? You only have about 30 days after the probable arrival to file an Item Not Received Dispute. This used to be 45 days after purchase.
If you bought anything in January, open a Dispute today. It certainly should have arrived by now.
If it has been more than 30 days since purchase in February, contact the seller as a firs step and ask for date of shipping , service used and tracking number.
Don't worry if there is no tracking number, that's much more important to him than to you.
And do NOT allow the seller to offer a replacement. This is a common scam, mostly from Asian sellers. There is not replacement and probably was no original item. This should be a prompt to open and pursue a Dispute.
