Be careful when strangers mention money. Just because we are sincere does not mean that others have no motive. As far as our general understanding is concerned, how can a few hundred dollars be owed when the phone is stopped by a mobile phone? If your friend is a high-quality customer of GSM, or his phone number has been protected for many years, then at least he values social reputation and has high-quality friends and social networks. Common sense reasoning analysis, you meet a scheming bitch liar. I suggest you stay away from such friends.