Be careful before you refund any money whatsoever.

They SAY they have paid but the money isn't in your account as yet and that is the main thing to keep in mind and I personally would answer their messages and say, 'Payment is not yet showing in my account. Please check with your bank and I will re-check on Monday. I only post items once payment has been received."

We used to sell years ago and numerous buyers-heaps of them-claimed to have paid. My sister used to just politely reply that payment was not showing, could they check. Usually they would answer with "I will pay tomorrow."

So they were lying, they had not paid at all.

In your case, I think either one of two things is happening.

1. Buyer may have paid via bank deposit but is anxious now that you might not follow through as they realise they have no paypal protection.

2. They haven't paid but are hoping to bluff you into posting the item or refunding money before you actually discover no payment has gone through.