I sold a dress on 25 May and posted second class on 27 May. Tonight I have received an email from eBay saying the buyer has opened a case against me as they have not received the item. No message from the buyer before this. I have proof of postage but it was just sent standard second class so its not tracked. I replied saying please check with the local post office and with neighbours as I have received positive feedback from other parcels sent at the same time and I have uploaded a picture of the proof of postage. I know that eBay usually finds in the buyer's favour and I'll probably have to end up refunding but how long should I wait before doing that? Royal Mail won't allow claims until 15 working days have passed.