Hi 
this is the first time I've sold an item on ebay. I have mainly used eBay for buying things.
It was listed as a buy it now but I agreed to a best offer.
Since then I PM'd the buyer to say that I would dispatch the item once payment received. The reply was that payment had already been sent

On my eBay account it says 'payment awaited' under the notifications section. On my PayPal account I can't see evidence of payment on the activity page. Nothing new in my bank account.
basically have I done something wrong? Would the payment show up somewhere else?
Thank you in advance