I have two transactions in my PayPal that say I've received the money but I never accepted them and can't find them in any of my bank accounts. The sender says that the money wasn't sent back to them either. So neither of us know where the money is.
As you have not added your country to your profile (so we can see when we hover over your username) or said in your post which country you are in then sadly can't advise. Paypal varies a great deal country to country so you need to tell us where you are on this worldwide community forum.
Advice is voluntary. Kudos / Solution appreciated.