Yes, you most likely can sue your friend, under one or more of the following theories: 1) breach of contract (he did not give you what you paid him for--a phone that would keep working); or 2) fraud (if he knew or reasonably should have known this would have happened and, knowing that, still misrepresented or lied to you). However, it is questionable whether it is worth the cost and time to sue over $105.