I just sold an iPhone on eBay, but i haven't received payment?

I made sure it was receive payment at once but my paypal or bank hasn't received the money for it? The buyer texted me but I was at work and just texted back, could they take back their payment or what's happening?

Don't text - use the message facility on ebay. That way if something goes wrong ebay can see at a glance what has been said.

Have a look on ebay now and see what's going on.

Hope you didn't send the item
plus it might have been scam or phising attempt
how did the ebay buyer know your phone number?