Looking for some advice - I recently sold my iPhone 3G on eBay and have since withdrawn the cash from PayPal into my bank account so that I could buy an iPhone 4. However, today I received an email from the buyer saying that the item is faulty because it keeps freezing and they would like a refund. The phone never used to freeze with me but it is 2 years old so can the buyer really use this as a reason to demand a refund? Do you think I will have a leg to stand on if I refuse?